diff --git a/.github/workflows/certora.yml b/.github/workflows/certora.yml
index 7a2c63b81a..6a8e714868 100644
--- a/.github/workflows/certora.yml
+++ b/.github/workflows/certora.yml
@@ -20,13 +20,13 @@ jobs:
         with: { java-version: "11", java-package: jre }
 
       - name: Install certora cli
-        run: pip install certora-cli==7.6.3
+        run: pip install certora-cli==7.17.2
 
       - name: Install solc
         run: |
-          wget https://github.com/ethereum/solidity/releases/download/v0.8.10/solc-static-linux
+          wget https://github.com/ethereum/solidity/releases/download/v0.8.19/solc-static-linux
           chmod +x solc-static-linux
-          sudo mv solc-static-linux /usr/local/bin/solc8.10
+          sudo mv solc-static-linux /usr/local/bin/solc8.19
 
       - name: Verify rule ${{ matrix.rule }}
         run: |
diff --git a/certora/confs/ccip.conf b/certora/confs/ccip.conf
index 02245a1353..6df7e32e37 100644
--- a/certora/confs/ccip.conf
+++ b/certora/confs/ccip.conf
@@ -13,7 +13,7 @@
     "process": "emv",
     "prover_args": ["-depth 10","-mediumTimeout 700"],
     "smt_timeout": "600",
-    "solc": "solc8.10",
+    "solc": "solc8.19",
     "verify": "UpgradeableLockReleaseTokenPool:certora/specs/ccip.spec",
     "rule_sanity": "basic",
     "msg": "CCIP"
diff --git a/contracts/foundry.toml b/contracts/foundry.toml
index c9b19de367..3ae4962578 100644
--- a/contracts/foundry.toml
+++ b/contracts/foundry.toml
@@ -16,6 +16,10 @@ gas_price = 1
 block_timestamp = 1234567890
 block_number = 12345
 
+[rpc_endpoints]
+sepolia = "https://sepolia.gateway.tenderly.co"
+arb_sepolia = "https://arbitrum-sepolia.gateway.tenderly.co"
+
 [profile.ccip]
 solc_version = '0.8.19'
 src = 'src/v0.8/ccip'
diff --git a/contracts/src/v0.8/ccip/pools/GHO/UpgradeableBurnMintTokenPool.sol b/contracts/src/v0.8/ccip/pools/GHO/UpgradeableBurnMintTokenPool.sol
index 33c42760b7..a5cecc0430 100644
--- a/contracts/src/v0.8/ccip/pools/GHO/UpgradeableBurnMintTokenPool.sol
+++ b/contracts/src/v0.8/ccip/pools/GHO/UpgradeableBurnMintTokenPool.sol
@@ -2,14 +2,12 @@
 pragma solidity ^0.8.0;
 
 import {Initializable} from "solidity-utils/contracts/transparent-proxy/Initializable.sol";
-
 import {ITypeAndVersion} from "../../../shared/interfaces/ITypeAndVersion.sol";
 import {IBurnMintERC20} from "../../../shared/token/ERC20/IBurnMintERC20.sol";
 
 import {UpgradeableTokenPool} from "./UpgradeableTokenPool.sol";
 import {UpgradeableBurnMintTokenPoolAbstract} from "./UpgradeableBurnMintTokenPoolAbstract.sol";
 import {RateLimiter} from "../../libraries/RateLimiter.sol";
-
 import {IRouter} from "../../interfaces/IRouter.sol";
 
 /// @title UpgradeableBurnMintTokenPool
@@ -19,6 +17,8 @@ import {IRouter} from "../../interfaces/IRouter.sol";
 /// - Implementation of Initializable to allow upgrades
 /// - Move of allowlist and router definition to initialization stage
 /// - Inclusion of rate limit admin who may configure rate limits in addition to owner
+/// - Modifications from inherited contract (see contract for more details):
+///   - UpgradeableTokenPool: Modify `onlyOnRamp` & `onlyOffRamp` modifier to accept transactions from ProxyPool
 contract UpgradeableBurnMintTokenPool is Initializable, UpgradeableBurnMintTokenPoolAbstract, ITypeAndVersion {
   error Unauthorized(address caller);
 
@@ -45,8 +45,7 @@ contract UpgradeableBurnMintTokenPool is Initializable, UpgradeableBurnMintToken
   /// @param allowlist A set of addresses allowed to trigger lockOrBurn as original senders
   /// @param router The address of the router
   function initialize(address owner, address[] memory allowlist, address router) public virtual initializer {
-    if (owner == address(0)) revert ZeroAddressNotAllowed();
-    if (router == address(0)) revert ZeroAddressNotAllowed();
+    if (owner == address(0) || router == address(0)) revert ZeroAddressNotAllowed();
     _transferOwnership(owner);
 
     s_router = IRouter(router);
diff --git a/contracts/src/v0.8/ccip/pools/GHO/UpgradeableLockReleaseTokenPool.sol b/contracts/src/v0.8/ccip/pools/GHO/UpgradeableLockReleaseTokenPool.sol
index 8001ae59fa..4a63ab26ba 100644
--- a/contracts/src/v0.8/ccip/pools/GHO/UpgradeableLockReleaseTokenPool.sol
+++ b/contracts/src/v0.8/ccip/pools/GHO/UpgradeableLockReleaseTokenPool.sol
@@ -2,7 +2,6 @@
 pragma solidity ^0.8.0;
 
 import {Initializable} from "solidity-utils/contracts/transparent-proxy/Initializable.sol";
-
 import {ITypeAndVersion} from "../../../shared/interfaces/ITypeAndVersion.sol";
 import {ILiquidityContainer} from "../../../rebalancer/interfaces/ILiquidityContainer.sol";
 
@@ -11,7 +10,6 @@ import {RateLimiter} from "../../libraries/RateLimiter.sol";
 
 import {IERC20} from "../../../vendor/openzeppelin-solidity/v4.8.3/contracts/token/ERC20/IERC20.sol";
 import {SafeERC20} from "../../../vendor/openzeppelin-solidity/v4.8.3/contracts/token/ERC20/utils/SafeERC20.sol";
-
 import {IRouter} from "../../interfaces/IRouter.sol";
 
 /// @title UpgradeableLockReleaseTokenPool
@@ -21,6 +19,8 @@ import {IRouter} from "../../interfaces/IRouter.sol";
 /// - Implementation of Initializable to allow upgrades
 /// - Move of allowlist and router definition to initialization stage
 /// - Addition of a bridge limit to regulate the maximum amount of tokens that can be transferred out (burned/locked)
+/// - Modifications from inherited contract (see contract for more details):
+///   - UpgradeableTokenPool: Modify `onlyOnRamp` & `onlyOffRamp` modifier to accept transactions from ProxyPool
 contract UpgradeableLockReleaseTokenPool is Initializable, UpgradeableTokenPool, ILiquidityContainer, ITypeAndVersion {
   using SafeERC20 for IERC20;
 
@@ -86,8 +86,7 @@ contract UpgradeableLockReleaseTokenPool is Initializable, UpgradeableTokenPool,
     address router,
     uint256 bridgeLimit
   ) public virtual initializer {
-    if (owner == address(0)) revert ZeroAddressNotAllowed();
-    if (router == address(0)) revert ZeroAddressNotAllowed();
+    if (owner == address(0) || router == address(0)) revert ZeroAddressNotAllowed();
     _transferOwnership(owner);
 
     s_router = IRouter(router);
diff --git a/contracts/src/v0.8/ccip/pools/GHO/UpgradeableTokenPool.sol b/contracts/src/v0.8/ccip/pools/GHO/UpgradeableTokenPool.sol
index ee359ac1f8..9c294974bc 100644
--- a/contracts/src/v0.8/ccip/pools/GHO/UpgradeableTokenPool.sol
+++ b/contracts/src/v0.8/ccip/pools/GHO/UpgradeableTokenPool.sol
@@ -12,9 +12,12 @@ import {IERC20} from "../../../vendor/openzeppelin-solidity/v4.8.3/contracts/tok
 import {IERC165} from "../../../vendor/openzeppelin-solidity/v4.8.3/contracts/utils/introspection/IERC165.sol";
 import {EnumerableSet} from "../../../vendor/openzeppelin-solidity/v4.8.3/contracts/utils/structs/EnumerableSet.sol";
 
-/// @notice Base abstract class with common functions for all token pools.
-/// A token pool serves as isolated place for holding tokens and token specific logic
-/// that may execute as tokens move across the bridge.
+/// @title UpgradeableTokenPool
+/// @author Aave Labs
+/// @notice Upgradeable version of Chainlink's CCIP TokenPool
+/// @dev Contract adaptations:
+///   - Setters & Getters for new ProxyPool (to support 1.5 CCIP migration on the existing 1.4 Pool)
+///   - Modify `onlyOnRamp` & `onlyOffRamp` modifier to accept transactions from ProxyPool
 abstract contract UpgradeableTokenPool is IPool, OwnerIsCreator, IERC165 {
   using EnumerableSet for EnumerableSet.AddressSet;
   using EnumerableSet for EnumerableSet.UintSet;
@@ -55,6 +58,12 @@ abstract contract UpgradeableTokenPool is IPool, OwnerIsCreator, IERC165 {
     RateLimiter.Config inboundRateLimiterConfig; // Inbound rate limited config, meaning the rate limits for all of the offRamps for the given chain
   }
 
+  /// @dev The storage slot for Proxy Pool address, act as an on ramp "wrapper" post ccip 1.5 migration.
+  /// @dev This was added to continue support for 1.2 onRamp during 1.5 migration, and is stored
+  /// this way to avoid storage collision.
+  // bytes32(uint256(keccak256("ccip.pools.GHO.UpgradeableTokenPool.proxyPool")) - 1)
+  bytes32 internal constant PROXY_POOL_SLOT = 0x75bb68f1b335d4dab6963140ecff58281174ef4362bb85a8593ab9379f24fae2;
+
   /// @dev The bridgeable token that is managed by this pool.
   IERC20 internal immutable i_token;
   /// @dev The address of the arm proxy
@@ -250,7 +259,9 @@ abstract contract UpgradeableTokenPool is IPool, OwnerIsCreator, IERC165 {
   /// is a permissioned onRamp for the given chain on the Router.
   modifier onlyOnRamp(uint64 remoteChainSelector) {
     if (!isSupportedChain(remoteChainSelector)) revert ChainNotAllowed(remoteChainSelector);
-    if (!(msg.sender == s_router.getOnRamp(remoteChainSelector))) revert CallerIsNotARampOnRouter(msg.sender);
+    if (!(msg.sender == getProxyPool() || msg.sender == s_router.getOnRamp(remoteChainSelector))) {
+      revert CallerIsNotARampOnRouter(msg.sender);
+    }
     _;
   }
 
@@ -258,7 +269,9 @@ abstract contract UpgradeableTokenPool is IPool, OwnerIsCreator, IERC165 {
   /// is a permissioned offRamp for the given chain on the Router.
   modifier onlyOffRamp(uint64 remoteChainSelector) {
     if (!isSupportedChain(remoteChainSelector)) revert ChainNotAllowed(remoteChainSelector);
-    if (!s_router.isOffRamp(remoteChainSelector, msg.sender)) revert CallerIsNotARampOnRouter(msg.sender);
+    if (!(msg.sender == getProxyPool() || s_router.isOffRamp(remoteChainSelector, msg.sender))) {
+      revert CallerIsNotARampOnRouter(msg.sender);
+    }
     _;
   }
 
@@ -317,4 +330,21 @@ abstract contract UpgradeableTokenPool is IPool, OwnerIsCreator, IERC165 {
     if (IARM(i_armProxy).isCursed()) revert BadARMSignal();
     _;
   }
+
+  /// @notice Getter for proxy pool address.
+  /// @return proxyPool The proxy pool address.
+  function getProxyPool() public view returns (address proxyPool) {
+    assembly ("memory-safe") {
+      proxyPool := shr(96, shl(96, sload(PROXY_POOL_SLOT)))
+    }
+  }
+
+  /// @notice Setter for proxy pool address, only callable by the DAO.
+  /// @param proxyPool The address of the proxy pool.
+  function setProxyPool(address proxyPool) external onlyOwner {
+    if (proxyPool == address(0)) revert ZeroAddressNotAllowed();
+    assembly ("memory-safe") {
+      sstore(PROXY_POOL_SLOT, proxyPool)
+    }
+  }
 }
diff --git a/contracts/src/v0.8/ccip/pools/GHO/diffs/UpgradeableBurnMintTokenPoolAbstract_diff.md b/contracts/src/v0.8/ccip/pools/GHO/diffs/UpgradeableBurnMintTokenPoolAbstract_diff.md
index 2255b2ca44..a1aa3e58c9 100644
--- a/contracts/src/v0.8/ccip/pools/GHO/diffs/UpgradeableBurnMintTokenPoolAbstract_diff.md
+++ b/contracts/src/v0.8/ccip/pools/GHO/diffs/UpgradeableBurnMintTokenPoolAbstract_diff.md
@@ -7,13 +7,13 @@ index f5eb135186..e228732855 100644
  // SPDX-License-Identifier: BUSL-1.1
 -pragma solidity 0.8.19;
 +pragma solidity ^0.8.0;
- 
+
 -import {IBurnMintERC20} from "../../shared/token/ERC20/IBurnMintERC20.sol";
 +import {IBurnMintERC20} from "../../../shared/token/ERC20/IBurnMintERC20.sol";
- 
+
 -import {TokenPool} from "./TokenPool.sol";
 +import {UpgradeableTokenPool} from "./UpgradeableTokenPool.sol";
- 
+
 -abstract contract BurnMintTokenPoolAbstract is TokenPool {
 +abstract contract UpgradeableBurnMintTokenPoolAbstract is UpgradeableTokenPool {
    /// @notice Contains the specific burn call for a pool.
diff --git a/contracts/src/v0.8/ccip/pools/GHO/diffs/UpgradeableBurnMintTokenPool_diff.md b/contracts/src/v0.8/ccip/pools/GHO/diffs/UpgradeableBurnMintTokenPool_diff.md
index 066847e4f8..3302bad675 100644
--- a/contracts/src/v0.8/ccip/pools/GHO/diffs/UpgradeableBurnMintTokenPool_diff.md
+++ b/contracts/src/v0.8/ccip/pools/GHO/diffs/UpgradeableBurnMintTokenPool_diff.md
@@ -1,26 +1,24 @@
 ```diff
 diff --git a/src/v0.8/ccip/pools/BurnMintTokenPool.sol b/src/v0.8/ccip/pools/GHO/UpgradeableBurnMintTokenPool.sol
-index 9af0f22f4c..a46ff915e5 100644
+index 9af0f22f4c..a5cecc0430 100644
 --- a/src/v0.8/ccip/pools/BurnMintTokenPool.sol
 +++ b/src/v0.8/ccip/pools/GHO/UpgradeableBurnMintTokenPool.sol
 @@ -1,28 +1,90 @@
  // SPDX-License-Identifier: BUSL-1.1
 -pragma solidity 0.8.19;
 +pragma solidity ^0.8.0;
- 
+
 -import {ITypeAndVersion} from "../../shared/interfaces/ITypeAndVersion.sol";
 -import {IBurnMintERC20} from "../../shared/token/ERC20/IBurnMintERC20.sol";
 +import {Initializable} from "solidity-utils/contracts/transparent-proxy/Initializable.sol";
- 
--import {TokenPool} from "./TokenPool.sol";
--import {BurnMintTokenPoolAbstract} from "./BurnMintTokenPoolAbstract.sol";
 +import {ITypeAndVersion} from "../../../shared/interfaces/ITypeAndVersion.sol";
 +import {IBurnMintERC20} from "../../../shared/token/ERC20/IBurnMintERC20.sol";
-+
+
+-import {TokenPool} from "./TokenPool.sol";
+-import {BurnMintTokenPoolAbstract} from "./BurnMintTokenPoolAbstract.sol";
 +import {UpgradeableTokenPool} from "./UpgradeableTokenPool.sol";
 +import {UpgradeableBurnMintTokenPoolAbstract} from "./UpgradeableBurnMintTokenPoolAbstract.sol";
 +import {RateLimiter} from "../../libraries/RateLimiter.sol";
-+
 +import {IRouter} from "../../interfaces/IRouter.sol";
 +
 +/// @title UpgradeableBurnMintTokenPool
@@ -29,9 +27,12 @@ index 9af0f22f4c..a46ff915e5 100644
 +/// @dev Contract adaptations:
 +/// - Implementation of Initializable to allow upgrades
 +/// - Move of allowlist and router definition to initialization stage
++/// - Inclusion of rate limit admin who may configure rate limits in addition to owner
++/// - Modifications from inherited contract (see contract for more details):
++///   - UpgradeableTokenPool: Modify `onlyOnRamp` & `onlyOffRamp` modifier to accept transactions from ProxyPool
 +contract UpgradeableBurnMintTokenPool is Initializable, UpgradeableBurnMintTokenPoolAbstract, ITypeAndVersion {
 +  error Unauthorized(address caller);
- 
+
 -/// @notice This pool mints and burns a 3rd-party token.
 -/// @dev Pool whitelisting mode is set in the constructor and cannot be modified later.
 -/// It either accepts any address as originalSender, or only accepts whitelisted originalSender.
@@ -39,7 +40,7 @@ index 9af0f22f4c..a46ff915e5 100644
 -/// If that is expected, please make sure the token's burner/minter roles are adjustable.
 -contract BurnMintTokenPool is BurnMintTokenPoolAbstract, ITypeAndVersion {
    string public constant override typeAndVersion = "BurnMintTokenPool 1.4.0";
- 
+
 +  /// @notice The address of the rate limiter admin.
 +  /// @dev Can be address(0) if none is configured.
 +  address internal s_rateLimitAdmin;
@@ -57,7 +58,7 @@ index 9af0f22f4c..a46ff915e5 100644
 -  ) TokenPool(token, allowlist, armProxy, router) {}
 +    bool allowlistEnabled
 +  ) UpgradeableTokenPool(IBurnMintERC20(token), armProxy, allowlistEnabled) {}
- 
+
 -  /// @inheritdoc BurnMintTokenPoolAbstract
 +  /// @dev Initializer
 +  /// @dev The address passed as `owner` must accept ownership after initialization.
@@ -66,8 +67,7 @@ index 9af0f22f4c..a46ff915e5 100644
 +  /// @param allowlist A set of addresses allowed to trigger lockOrBurn as original senders
 +  /// @param router The address of the router
 +  function initialize(address owner, address[] memory allowlist, address router) public virtual initializer {
-+    if (owner == address(0)) revert ZeroAddressNotAllowed();
-+    if (router == address(0)) revert ZeroAddressNotAllowed();
++    if (owner == address(0) || router == address(0)) revert ZeroAddressNotAllowed();
 +    _transferOwnership(owner);
 +
 +    s_router = IRouter(router);
@@ -90,7 +90,7 @@ index 9af0f22f4c..a46ff915e5 100644
 +    return s_rateLimitAdmin;
 +  }
 +
-+  /// @notice Sets the rate limiter admin address.
++  /// @notice Sets the chain rate limiter config.
 +  /// @dev Only callable by the owner or the rate limiter admin. NOTE: overwrites the normal
 +  /// onlyAdmin check in the base implementation to also allow the rate limiter admin.
 +  /// @param remoteChainSelector The remote chain selector for which the rate limits apply.
diff --git a/contracts/src/v0.8/ccip/pools/GHO/diffs/UpgradeableLockReleaseTokenPool_diff.md b/contracts/src/v0.8/ccip/pools/GHO/diffs/UpgradeableLockReleaseTokenPool_diff.md
index 1e738e3bdf..4275c54339 100644
--- a/contracts/src/v0.8/ccip/pools/GHO/diffs/UpgradeableLockReleaseTokenPool_diff.md
+++ b/contracts/src/v0.8/ccip/pools/GHO/diffs/UpgradeableLockReleaseTokenPool_diff.md
@@ -1,37 +1,35 @@
 ```diff
 diff --git a/src/v0.8/ccip/pools/LockReleaseTokenPool.sol b/src/v0.8/ccip/pools/GHO/UpgradeableLockReleaseTokenPool.sol
-index 1a17fa0398..9a30b1e977 100644
+index 1a17fa0398..4a63ab26ba 100644
 --- a/src/v0.8/ccip/pools/LockReleaseTokenPool.sol
 +++ b/src/v0.8/ccip/pools/GHO/UpgradeableLockReleaseTokenPool.sol
 @@ -1,26 +1,39 @@
  // SPDX-License-Identifier: BUSL-1.1
 -pragma solidity 0.8.19;
 +pragma solidity ^0.8.0;
- 
+
 -import {ITypeAndVersion} from "../../shared/interfaces/ITypeAndVersion.sol";
 -import {ILiquidityContainer} from "../../rebalancer/interfaces/ILiquidityContainer.sol";
 +import {Initializable} from "solidity-utils/contracts/transparent-proxy/Initializable.sol";
- 
--import {TokenPool} from "./TokenPool.sol";
--import {RateLimiter} from "../libraries/RateLimiter.sol";
 +import {ITypeAndVersion} from "../../../shared/interfaces/ITypeAndVersion.sol";
 +import {ILiquidityContainer} from "../../../rebalancer/interfaces/ILiquidityContainer.sol";
- 
--import {IERC20} from "../../vendor/openzeppelin-solidity/v4.8.3/contracts/token/ERC20/IERC20.sol";
--import {SafeERC20} from "../../vendor/openzeppelin-solidity/v4.8.3/contracts/token/ERC20/utils/SafeERC20.sol";
+
+-import {TokenPool} from "./TokenPool.sol";
+-import {RateLimiter} from "../libraries/RateLimiter.sol";
 +import {UpgradeableTokenPool} from "./UpgradeableTokenPool.sol";
 +import {RateLimiter} from "../../libraries/RateLimiter.sol";
- 
+
+-import {IERC20} from "../../vendor/openzeppelin-solidity/v4.8.3/contracts/token/ERC20/IERC20.sol";
+-import {SafeERC20} from "../../vendor/openzeppelin-solidity/v4.8.3/contracts/token/ERC20/utils/SafeERC20.sol";
++import {IERC20} from "../../../vendor/openzeppelin-solidity/v4.8.3/contracts/token/ERC20/IERC20.sol";
++import {SafeERC20} from "../../../vendor/openzeppelin-solidity/v4.8.3/contracts/token/ERC20/utils/SafeERC20.sol";
++import {IRouter} from "../../interfaces/IRouter.sol";
+
 -/// @notice Token pool used for tokens on their native chain. This uses a lock and release mechanism.
 -/// Because of lock/unlock requiring liquidity, this pool contract also has function to add and remove
 -/// liquidity. This allows for proper bookkeeping for both user and liquidity provider balances.
 -/// @dev One token per LockReleaseTokenPool.
 -contract LockReleaseTokenPool is TokenPool, ILiquidityContainer, ITypeAndVersion {
-+import {IERC20} from "../../../vendor/openzeppelin-solidity/v4.8.3/contracts/token/ERC20/IERC20.sol";
-+import {SafeERC20} from "../../../vendor/openzeppelin-solidity/v4.8.3/contracts/token/ERC20/utils/SafeERC20.sol";
-+
-+import {IRouter} from "../../interfaces/IRouter.sol";
-+
 +/// @title UpgradeableLockReleaseTokenPool
 +/// @author Aave Labs
 +/// @notice Upgradeable version of Chainlink's CCIP LockReleaseTokenPool
@@ -39,13 +37,15 @@ index 1a17fa0398..9a30b1e977 100644
 +/// - Implementation of Initializable to allow upgrades
 +/// - Move of allowlist and router definition to initialization stage
 +/// - Addition of a bridge limit to regulate the maximum amount of tokens that can be transferred out (burned/locked)
++/// - Modifications from inherited contract (see contract for more details):
++///   - UpgradeableTokenPool: Modify `onlyOnRamp` & `onlyOffRamp` modifier to accept transactions from ProxyPool
 +contract UpgradeableLockReleaseTokenPool is Initializable, UpgradeableTokenPool, ILiquidityContainer, ITypeAndVersion {
    using SafeERC20 for IERC20;
- 
+
    error InsufficientLiquidity();
    error LiquidityNotAccepted();
    error Unauthorized(address caller);
- 
+
 +  error BridgeLimitExceeded(uint256 bridgeLimit);
 +  error NotEnoughBridgedAmount();
 +
@@ -53,12 +53,12 @@ index 1a17fa0398..9a30b1e977 100644
 +  event BridgeLimitAdminUpdated(address indexed oldAdmin, address indexed newAdmin);
 +
    string public constant override typeAndVersion = "LockReleaseTokenPool 1.4.0";
- 
+
    /// @dev The unique lock release pool flag to signal through EIP 165.
-@@ -37,16 +50,55 @@ contract LockReleaseTokenPool is TokenPool, ILiquidityContainer, ITypeAndVersion
+@@ -37,16 +50,54 @@ contract LockReleaseTokenPool is TokenPool, ILiquidityContainer, ITypeAndVersion
    /// @dev Can be address(0) if none is configured.
    address internal s_rateLimitAdmin;
- 
+
 +  /// @notice Maximum amount of tokens that can be bridged to other chains
 +  uint256 private s_bridgeLimit;
 +  /// @notice Amount of tokens bridged (transferred out)
@@ -86,7 +86,7 @@ index 1a17fa0398..9a30b1e977 100644
 +  ) UpgradeableTokenPool(IERC20(token), armProxy, allowlistEnabled) {
      i_acceptLiquidity = acceptLiquidity;
    }
- 
+
 +  /// @dev Initializer
 +  /// @dev The address passed as `owner` must accept ownership after initialization.
 +  /// @dev The `allowlist` is only effective if pool is set to access-controlled mode
@@ -100,8 +100,7 @@ index 1a17fa0398..9a30b1e977 100644
 +    address router,
 +    uint256 bridgeLimit
 +  ) public virtual initializer {
-+    if (owner == address(0)) revert ZeroAddressNotAllowed();
-+    if (router == address(0)) revert ZeroAddressNotAllowed();
++    if (owner == address(0) || router == address(0)) revert ZeroAddressNotAllowed();
 +    _transferOwnership(owner);
 +
 +    s_router = IRouter(router);
@@ -116,7 +115,7 @@ index 1a17fa0398..9a30b1e977 100644
    /// @notice Locks the token in the pool
    /// @param amount Amount to lock
    /// @dev The whenHealthy check is important to ensure that even if a ramp is compromised
-@@ -66,6 +118,9 @@ contract LockReleaseTokenPool is TokenPool, ILiquidityContainer, ITypeAndVersion
+@@ -66,6 +117,9 @@ contract LockReleaseTokenPool is TokenPool, ILiquidityContainer, ITypeAndVersion
      whenHealthy
      returns (bytes memory)
    {
@@ -126,7 +125,7 @@ index 1a17fa0398..9a30b1e977 100644
      _consumeOutboundRateLimit(remoteChainSelector, amount);
      emit Locked(msg.sender, amount);
      return "";
-@@ -83,6 +138,11 @@ contract LockReleaseTokenPool is TokenPool, ILiquidityContainer, ITypeAndVersion
+@@ -83,6 +137,11 @@ contract LockReleaseTokenPool is TokenPool, ILiquidityContainer, ITypeAndVersion
      uint64 remoteChainSelector,
      bytes memory
    ) external virtual override onlyOffRamp(remoteChainSelector) whenHealthy {
@@ -138,10 +137,10 @@ index 1a17fa0398..9a30b1e977 100644
      _consumeInboundRateLimit(remoteChainSelector, amount);
      getToken().safeTransfer(receiver, amount);
      emit Released(msg.sender, receiver, amount);
-@@ -120,11 +180,48 @@ contract LockReleaseTokenPool is TokenPool, ILiquidityContainer, ITypeAndVersion
+@@ -120,11 +179,48 @@ contract LockReleaseTokenPool is TokenPool, ILiquidityContainer, ITypeAndVersion
      s_rateLimitAdmin = rateLimitAdmin;
    }
- 
+
 +  /// @notice Sets the bridge limit, the maximum amount of tokens that can be bridged out
 +  /// @dev Only callable by the owner or the bridge limit admin.
 +  /// @dev Bridge limit changes should be carefully managed, specially when reducing below the current bridged amount
@@ -178,7 +177,7 @@ index 1a17fa0398..9a30b1e977 100644
    function getRateLimitAdmin() external view returns (address) {
      return s_rateLimitAdmin;
    }
- 
+
 +  /// @notice Gets the bridge limiter admin address.
 +  function getBridgeLimitAdmin() external view returns (address) {
 +    return s_bridgeLimitAdmin;
@@ -187,4 +186,13 @@ index 1a17fa0398..9a30b1e977 100644
    /// @notice Checks if the pool can accept liquidity.
    /// @return true if the pool can accept liquidity, false otherwise.
    function canAcceptLiquidity() external view returns (bool) {
+@@ -151,7 +247,7 @@ contract LockReleaseTokenPool is TokenPool, ILiquidityContainer, ITypeAndVersion
+     emit LiquidityRemoved(msg.sender, amount);
+   }
+
+-  /// @notice Sets the rate limiter admin address.
++  /// @notice Sets the chain rate limiter config.
+   /// @dev Only callable by the owner or the rate limiter admin. NOTE: overwrites the normal
+   /// onlyAdmin check in the base implementation to also allow the rate limiter admin.
+   /// @param remoteChainSelector The remote chain selector for which the rate limits apply.
 ```
diff --git a/contracts/src/v0.8/ccip/pools/GHO/diffs/UpgradeableTokenPool_diff.md b/contracts/src/v0.8/ccip/pools/GHO/diffs/UpgradeableTokenPool_diff.md
index fcdc197580..c5bb382c46 100644
--- a/contracts/src/v0.8/ccip/pools/GHO/diffs/UpgradeableTokenPool_diff.md
+++ b/contracts/src/v0.8/ccip/pools/GHO/diffs/UpgradeableTokenPool_diff.md
@@ -1,41 +1,60 @@
 ```diff
 diff --git a/src/v0.8/ccip/pools/TokenPool.sol b/src/v0.8/ccip/pools/GHO/UpgradeableTokenPool.sol
-index b3571bb449..ee359ac1f8 100644
+index b3571bb449..9c294974bc 100644
 --- a/src/v0.8/ccip/pools/TokenPool.sol
 +++ b/src/v0.8/ccip/pools/GHO/UpgradeableTokenPool.sol
-@@ -1,21 +1,21 @@
+@@ -1,21 +1,24 @@
  // SPDX-License-Identifier: BUSL-1.1
 -pragma solidity 0.8.19;
 +pragma solidity ^0.8.0;
- 
+
 -import {IPool} from "../interfaces/pools/IPool.sol";
 -import {IARM} from "../interfaces/IARM.sol";
 -import {IRouter} from "../interfaces/IRouter.sol";
 +import {IPool} from "../../interfaces/pools/IPool.sol";
 +import {IARM} from "../../interfaces/IARM.sol";
 +import {IRouter} from "../../interfaces/IRouter.sol";
- 
+
 -import {OwnerIsCreator} from "../../shared/access/OwnerIsCreator.sol";
 -import {RateLimiter} from "../libraries/RateLimiter.sol";
 +import {OwnerIsCreator} from "../../../shared/access/OwnerIsCreator.sol";
 +import {RateLimiter} from "../../libraries/RateLimiter.sol";
- 
+
 -import {IERC20} from "../../vendor/openzeppelin-solidity/v4.8.3/contracts/token/ERC20/IERC20.sol";
 -import {IERC165} from "../../vendor/openzeppelin-solidity/v4.8.3/contracts/utils/introspection/IERC165.sol";
 -import {EnumerableSet} from "../../vendor/openzeppelin-solidity/v4.8.3/contracts/utils/structs/EnumerableSet.sol";
 +import {IERC20} from "../../../vendor/openzeppelin-solidity/v4.8.3/contracts/token/ERC20/IERC20.sol";
 +import {IERC165} from "../../../vendor/openzeppelin-solidity/v4.8.3/contracts/utils/introspection/IERC165.sol";
 +import {EnumerableSet} from "../../../vendor/openzeppelin-solidity/v4.8.3/contracts/utils/structs/EnumerableSet.sol";
- 
- /// @notice Base abstract class with common functions for all token pools.
- /// A token pool serves as isolated place for holding tokens and token specific logic
- /// that may execute as tokens move across the bridge.
+
+-/// @notice Base abstract class with common functions for all token pools.
+-/// A token pool serves as isolated place for holding tokens and token specific logic
+-/// that may execute as tokens move across the bridge.
 -abstract contract TokenPool is IPool, OwnerIsCreator, IERC165 {
++/// @title UpgradeableTokenPool
++/// @author Aave Labs
++/// @notice Upgradeable version of Chainlink's CCIP TokenPool
++/// @dev Contract adaptations:
++///   - Setters & Getters for new ProxyPool (to support 1.5 CCIP migration on the existing 1.4 Pool)
++///   - Modify `onlyOnRamp` & `onlyOffRamp` modifier to accept transactions from ProxyPool
 +abstract contract UpgradeableTokenPool is IPool, OwnerIsCreator, IERC165 {
    using EnumerableSet for EnumerableSet.AddressSet;
    using EnumerableSet for EnumerableSet.UintSet;
    using RateLimiter for RateLimiter.TokenBucket;
-@@ -74,23 +74,17 @@ abstract contract TokenPool is IPool, OwnerIsCreator, IERC165 {
+@@ -55,6 +58,12 @@ abstract contract TokenPool is IPool, OwnerIsCreator, IERC165 {
+     RateLimiter.Config inboundRateLimiterConfig; // Inbound rate limited config, meaning the rate limits for all of the offRamps for the given chain
+   }
+
++  /// @dev The storage slot for Proxy Pool address, act as an on ramp "wrapper" post ccip 1.5 migration.
++  /// @dev This was added to continue support for 1.2 onRamp during 1.5 migration, and is stored
++  /// this way to avoid storage collision.
++  // bytes32(uint256(keccak256("ccip.pools.GHO.UpgradeableTokenPool.proxyPool")) - 1)
++  bytes32 internal constant PROXY_POOL_SLOT = 0x75bb68f1b335d4dab6963140ecff58281174ef4362bb85a8593ab9379f24fae2;
++
+   /// @dev The bridgeable token that is managed by this pool.
+   IERC20 internal immutable i_token;
+   /// @dev The address of the arm proxy
+@@ -74,23 +83,17 @@ abstract contract TokenPool is IPool, OwnerIsCreator, IERC165 {
    EnumerableSet.UintSet internal s_remoteChainSelectors;
    /// @dev Outbound rate limits. Corresponds to the inbound rate limit for the pool
    /// on the remote chain.
@@ -46,7 +65,7 @@ index b3571bb449..ee359ac1f8 100644
    /// degrees and prefer different limits)
 -  mapping(uint64 remoteChainSelector => RateLimiter.TokenBucket) internal s_inboundRateLimits;
 +  mapping(uint64 => RateLimiter.TokenBucket) internal s_inboundRateLimits;
- 
+
 -  constructor(IERC20 token, address[] memory allowlist, address armProxy, address router) {
 -    if (address(token) == address(0) || router == address(0)) revert ZeroAddressNotAllowed();
 +  constructor(IERC20 token, address armProxy, bool allowlistEnabled) {
@@ -62,6 +81,50 @@ index b3571bb449..ee359ac1f8 100644
 -    }
 +    i_allowlistEnabled = allowlistEnabled;
    }
- 
+
    /// @notice Get ARM proxy address
+@@ -256,7 +259,9 @@ abstract contract TokenPool is IPool, OwnerIsCreator, IERC165 {
+   /// is a permissioned onRamp for the given chain on the Router.
+   modifier onlyOnRamp(uint64 remoteChainSelector) {
+     if (!isSupportedChain(remoteChainSelector)) revert ChainNotAllowed(remoteChainSelector);
+-    if (!(msg.sender == s_router.getOnRamp(remoteChainSelector))) revert CallerIsNotARampOnRouter(msg.sender);
++    if (!(msg.sender == getProxyPool() || msg.sender == s_router.getOnRamp(remoteChainSelector))) {
++      revert CallerIsNotARampOnRouter(msg.sender);
++    }
+     _;
+   }
+
+@@ -264,7 +269,9 @@ abstract contract TokenPool is IPool, OwnerIsCreator, IERC165 {
+   /// is a permissioned offRamp for the given chain on the Router.
+   modifier onlyOffRamp(uint64 remoteChainSelector) {
+     if (!isSupportedChain(remoteChainSelector)) revert ChainNotAllowed(remoteChainSelector);
+-    if (!s_router.isOffRamp(remoteChainSelector, msg.sender)) revert CallerIsNotARampOnRouter(msg.sender);
++    if (!(msg.sender == getProxyPool() || s_router.isOffRamp(remoteChainSelector, msg.sender))) {
++      revert CallerIsNotARampOnRouter(msg.sender);
++    }
+     _;
+   }
+
+@@ -323,4 +330,21 @@ abstract contract TokenPool is IPool, OwnerIsCreator, IERC165 {
+     if (IARM(i_armProxy).isCursed()) revert BadARMSignal();
+     _;
+   }
++
++  /// @notice Getter for proxy pool address.
++  /// @return proxyPool The proxy pool address.
++  function getProxyPool() public view returns (address proxyPool) {
++    assembly ("memory-safe") {
++      proxyPool := shr(96, shl(96, sload(PROXY_POOL_SLOT)))
++    }
++  }
++
++  /// @notice Setter for proxy pool address, only callable by the DAO.
++  /// @param proxyPool The address of the proxy pool.
++  function setProxyPool(address proxyPool) external onlyOwner {
++    if (proxyPool == address(0)) revert ZeroAddressNotAllowed();
++    assembly ("memory-safe") {
++      sstore(PROXY_POOL_SLOT, proxyPool)
++    }
++  }
+ }
 ```
diff --git a/contracts/src/v0.8/ccip/test/helpers/interfaces/IEVM2EVMOffRamp.sol b/contracts/src/v0.8/ccip/test/helpers/interfaces/IEVM2EVMOffRamp.sol
new file mode 100644
index 0000000000..6b370fbcee
--- /dev/null
+++ b/contracts/src/v0.8/ccip/test/helpers/interfaces/IEVM2EVMOffRamp.sol
@@ -0,0 +1,17 @@
+pragma solidity ^0.8.0;
+
+import {ITypeAndVersion} from "../../../../shared/interfaces/ITypeAndVersion.sol";
+import {IAny2EVMOffRamp} from "../../../interfaces/IAny2EVMOffRamp.sol";
+import {Internal} from "../../../libraries/Internal.sol";
+
+interface IEVM2EVMOffRamp_1_2 is IAny2EVMOffRamp, ITypeAndVersion {
+  function executeSingleMessage(Internal.EVM2EVMMessage memory message, bytes[] memory offchainTokenData) external;
+}
+
+interface IEVM2EVMOffRamp_1_5 is IAny2EVMOffRamp, ITypeAndVersion {
+  function executeSingleMessage(
+    Internal.EVM2EVMMessage calldata message,
+    bytes[] calldata offchainTokenData,
+    uint32[] memory tokenGasOverrides
+  ) external;
+}
diff --git a/contracts/src/v0.8/ccip/test/helpers/interfaces/IEVM2EVMOnRamp.sol b/contracts/src/v0.8/ccip/test/helpers/interfaces/IEVM2EVMOnRamp.sol
new file mode 100644
index 0000000000..4fa742dae4
--- /dev/null
+++ b/contracts/src/v0.8/ccip/test/helpers/interfaces/IEVM2EVMOnRamp.sol
@@ -0,0 +1,46 @@
+pragma solidity ^0.8.0;
+
+import {ITypeAndVersion} from "../../../../shared/interfaces/ITypeAndVersion.sol";
+import {IEVM2AnyOnRamp} from "../../../interfaces/IEVM2AnyOnRamp.sol";
+
+interface IEVM2EVMOnRamp_1_2 is IEVM2AnyOnRamp, ITypeAndVersion {}
+
+interface IEVM2EVMOnRamp_1_5 is IEVM2AnyOnRamp, ITypeAndVersion {
+  struct TokenTransferFeeConfig {
+    uint32 minFeeUSDCents; // ──────────╮ Minimum fee to charge per token transfer, multiples of 0.01 USD
+    uint32 maxFeeUSDCents; //           │ Maximum fee to charge per token transfer, multiples of 0.01 USD
+    uint16 deciBps; //                  │ Basis points charged on token transfers, multiples of 0.1bps, or 1e-5
+    uint32 destGasOverhead; //          │ Gas charged to execute the token transfer on the destination chain
+    //                                  │ Extra data availability bytes that are returned from the source pool and sent
+    uint32 destBytesOverhead; //        │ to the destination pool. Must be >= Pool.CCIP_LOCK_OR_BURN_V1_RET_BYTES
+    bool aggregateRateLimitEnabled; //  │ Whether this transfer token is to be included in Aggregate Rate Limiting
+    bool isEnabled; // ─────────────────╯ Whether this token has custom transfer fees
+  }
+
+  struct DynamicConfig {
+    address router; // ──────────────────────────╮ Router address
+    uint16 maxNumberOfTokensPerMsg; //           │ Maximum number of distinct ERC20 token transferred per message
+    uint32 destGasOverhead; //                   │ Gas charged on top of the gasLimit to cover destination chain costs
+    uint16 destGasPerPayloadByte; //             │ Destination chain gas charged for passing each byte of `data` payload to receiver
+    uint32 destDataAvailabilityOverheadGas; // ──╯ Extra data availability gas charged on top of the message, e.g. for OCR
+    uint16 destGasPerDataAvailabilityByte; // ───╮ Amount of gas to charge per byte of message data that needs availability
+    uint16 destDataAvailabilityMultiplierBps; // │ Multiplier for data availability gas, multiples of bps, or 0.0001
+    address priceRegistry; //                    │ Price registry address
+    uint32 maxDataBytes; //                      │ Maximum payload data size in bytes
+    uint32 maxPerMsgGasLimit; // ────────────────╯ Maximum gas limit for messages targeting EVMs
+    //                                           │
+    // The following three properties are defaults, they can be overridden by setting the TokenTransferFeeConfig for a token
+    uint16 defaultTokenFeeUSDCents; // ──────────╮ Default token fee charged per token transfer
+    uint32 defaultTokenDestGasOverhead; //       │ Default gas charged to execute the token transfer on the destination chain
+    bool enforceOutOfOrder; // ──────────────────╯ Whether to enforce the allowOutOfOrderExecution extraArg value to be true.
+  }
+
+  /// @notice Gets the transfer fee config for a given token.
+  function getTokenTransferFeeConfig(
+    address token
+  ) external view returns (TokenTransferFeeConfig memory tokenTransferFeeConfig);
+
+  /// @notice Returns the dynamic onRamp config.
+  /// @return dynamicConfig the configuration.
+  function getDynamicConfig() external view returns (DynamicConfig memory dynamicConfig);
+}
diff --git a/contracts/src/v0.8/ccip/test/pools/GHO/GhoTokenPoolRemote.t.sol b/contracts/src/v0.8/ccip/test/pools/GHO/GhoTokenPoolRemote.t.sol
index 773528c715..deba3b745b 100644
--- a/contracts/src/v0.8/ccip/test/pools/GHO/GhoTokenPoolRemote.t.sol
+++ b/contracts/src/v0.8/ccip/test/pools/GHO/GhoTokenPoolRemote.t.sol
@@ -376,3 +376,25 @@ contract GhoTokenPoolRemote_setRateLimitAdmin is GhoTokenPoolRemoteSetup {
     s_pool.setRateLimitAdmin(STRANGER);
   }
 }
+
+contract GhoTokenPoolRemote_proxyPool is GhoTokenPoolRemoteSetup {
+  function testSetProxyPoolAdminReverts() public {
+    vm.startPrank(STRANGER);
+    vm.expectRevert("Only callable by owner");
+    s_pool.setProxyPool(makeAddr("proxyPool"));
+  }
+
+  function testSetProxyPoolZeroAddressReverts() public {
+    vm.startPrank(AAVE_DAO);
+    vm.expectRevert(UpgradeableTokenPool.ZeroAddressNotAllowed.selector);
+    s_pool.setProxyPool(address(0));
+  }
+
+  function testSetProxyPoolSuccess(address proxyPool) public {
+    vm.assume(proxyPool != address(0));
+    changePrank(AAVE_DAO);
+    s_pool.setProxyPool(proxyPool);
+
+    assertEq(s_pool.getProxyPool(), proxyPool);
+  }
+}
diff --git a/contracts/src/v0.8/ccip/test/pools/GHO/fork/GhoTokenPoolMigrate1_4To1_5/ForkBase.t.sol b/contracts/src/v0.8/ccip/test/pools/GHO/fork/GhoTokenPoolMigrate1_4To1_5/ForkBase.t.sol
new file mode 100644
index 0000000000..a3c97a0b64
--- /dev/null
+++ b/contracts/src/v0.8/ccip/test/pools/GHO/fork/GhoTokenPoolMigrate1_4To1_5/ForkBase.t.sol
@@ -0,0 +1,450 @@
+// SPDX-License-Identifier: BUSL-1.1
+pragma solidity 0.8.19;
+
+import {Test} from "forge-std/Test.sol";
+import {IERC20} from "../../../../../../vendor/openzeppelin-solidity/v4.8.3/contracts/token/ERC20/IERC20.sol";
+import {ITypeAndVersion} from "../../../../../../shared/interfaces/ITypeAndVersion.sol";
+import {IRouterClient} from "../../../../../interfaces/IRouterClient.sol";
+import {IEVM2AnyOnRamp} from "../../../../../interfaces/IEVM2AnyOnRamp.sol";
+import {IRouter as IRouterBase} from "../../../../../interfaces/IRouter.sol";
+import {Client} from "../../../../../libraries/Client.sol";
+import {Internal} from "../../../../../libraries/Internal.sol";
+import {IEVM2EVMOffRamp_1_2, IEVM2EVMOffRamp_1_5} from "../../../../helpers/interfaces/IEVM2EVMOffRamp.sol";
+import {IEVM2EVMOnRamp_1_2, IEVM2EVMOnRamp_1_5} from "../../../../helpers/interfaces/IEVM2EVMOnRamp.sol";
+import {UpgradeableLockReleaseTokenPool_Sepolia} from "./LegacyTestnetTokenPools/UpgradeableLockReleaseTokenPool_Sepolia.sol";
+import {UpgradeableBurnMintTokenPool_ArbSepolia} from "./LegacyTestnetTokenPools/UpgradeableBurnMintTokenPool_ArbSepolia.sol";
+
+interface IRouter is IRouterClient, IRouterBase {
+  struct OffRamp {
+    uint64 sourceChainSelector;
+    address offRamp;
+  }
+  function getWrappedNative() external view returns (address);
+  function isOffRamp(uint64, address) external view returns (bool);
+  function getOffRamps() external view returns (OffRamp[] memory);
+}
+
+struct SourceTokenData {
+  bytes sourcePoolAddress;
+  bytes destTokenAddress;
+  bytes extraData;
+  uint32 destGasAmount;
+}
+
+contract ForkBase is Test {
+  error CallerIsNotARampOnRouter(address caller);
+
+  event CCIPSendRequested(Internal.EVM2EVMMessage message);
+  event Locked(address indexed sender, uint256 amount);
+  event Burned(address indexed sender, uint256 amount);
+  event Released(address indexed sender, address indexed recipient, uint256 amount);
+  event Minted(address indexed sender, address indexed recipient, uint256 amount);
+
+  struct L1 {
+    UpgradeableLockReleaseTokenPool_Sepolia tokenPool;
+    IRouter router;
+    IERC20 token;
+    IEVM2EVMOnRamp_1_2 EVM2EVMOnRamp1_2;
+    IEVM2EVMOnRamp_1_5 EVM2EVMOnRamp1_5;
+    IEVM2EVMOffRamp_1_2 EVM2EVMOffRamp1_2;
+    IEVM2EVMOffRamp_1_5 EVM2EVMOffRamp1_5;
+    address proxyPool;
+    uint64 chainSelector;
+    bytes32 metadataHash;
+    uint256 forkId;
+  }
+  struct L2 {
+    UpgradeableBurnMintTokenPool_ArbSepolia tokenPool;
+    IRouter router;
+    IERC20 token;
+    IEVM2EVMOnRamp_1_2 EVM2EVMOnRamp1_2;
+    IEVM2EVMOnRamp_1_5 EVM2EVMOnRamp1_5;
+    IEVM2EVMOffRamp_1_2 EVM2EVMOffRamp1_2;
+    IEVM2EVMOffRamp_1_5 EVM2EVMOffRamp1_5;
+    address proxyPool;
+    uint64 chainSelector;
+    bytes32 metadataHash;
+    uint256 forkId;
+  }
+
+  L1 internal l1;
+  L2 internal l2;
+
+  address internal alice = makeAddr("alice");
+
+  uint256 internal constant BLOCK_AFTER_MIGRATION_L1 = 6884195;
+  uint256 internal constant BLOCK_AFTER_MIGRATION_L2 = 89058935;
+
+  function setUp() public virtual {
+    l1.forkId = vm.createFork(vm.rpcUrl("sepolia"), BLOCK_AFTER_MIGRATION_L1);
+    l2.forkId = vm.createFork(vm.rpcUrl("arb_sepolia"), BLOCK_AFTER_MIGRATION_L2);
+
+    vm.selectFork(l1.forkId);
+    l1.tokenPool = UpgradeableLockReleaseTokenPool_Sepolia(0x7768248E1Ff75612c18324bad06bb393c1206980);
+    l1.proxyPool = 0x14A3298f667CCB3ad4B77878d80b353f6A10F183;
+    l1.router = IRouter(l1.tokenPool.getRouter());
+    l2.chainSelector = l1.tokenPool.getSupportedChains()[0];
+    l1.token = l1.tokenPool.getToken();
+    l1.EVM2EVMOnRamp1_2 = IEVM2EVMOnRamp_1_2(0xe4Dd3B16E09c016402585a8aDFdB4A18f772a07e); // legacy on ramp
+    l1.EVM2EVMOnRamp1_5 = IEVM2EVMOnRamp_1_5(l1.router.getOnRamp(l2.chainSelector));
+    l1.EVM2EVMOffRamp1_2 = IEVM2EVMOffRamp_1_2(0xF18896AB20a09A29e64fdEbA99FDb8EC328f43b1);
+    l1.EVM2EVMOffRamp1_5 = IEVM2EVMOffRamp_1_5(0xD2f5edfD4561d6E7599F6c6888Bd353cAFd0c55E);
+    vm.prank(alice);
+    l1.token.approve(address(l1.router), type(uint256).max);
+    deal(address(l1.token), alice, 1000e18);
+    deal(alice, 1000e18);
+
+    vm.selectFork(l2.forkId);
+    l2.tokenPool = UpgradeableBurnMintTokenPool_ArbSepolia(0x3eC2b6F818B72442fc36561e9F930DD2b60957D2);
+    l2.proxyPool = 0x2BDbDCC0957E8d9f5Eb1Fe8E1Bc0d7F57AD1C897;
+    l2.router = IRouter(l2.tokenPool.getRouter());
+    l1.chainSelector = l2.tokenPool.getSupportedChains()[0];
+    l2.token = l2.tokenPool.getToken();
+    l2.EVM2EVMOnRamp1_2 = IEVM2EVMOnRamp_1_2(0x4205E1Ca0202A248A5D42F5975A8FE56F3E302e9); // legacy on ramp
+    l2.EVM2EVMOnRamp1_5 = IEVM2EVMOnRamp_1_5(l2.router.getOnRamp(l1.chainSelector));
+    l2.EVM2EVMOffRamp1_2 = IEVM2EVMOffRamp_1_2(0x1c71f141b4630EBE52d6aF4894812960abE207eB);
+    l2.EVM2EVMOffRamp1_5 = IEVM2EVMOffRamp_1_5(0xBed6e9131916d724418C8a6FE810F727302a5c00);
+    vm.prank(alice);
+    l2.token.approve(address(l2.router), type(uint256).max);
+    deal(address(l2.token), alice, 1000e18);
+    deal(alice, 1000e18);
+
+    l1.metadataHash = _generateMetadataHash(l1.chainSelector, l1.EVM2EVMOnRamp1_5);
+    l2.metadataHash = _generateMetadataHash(l2.chainSelector, l2.EVM2EVMOnRamp1_5);
+
+    vm.selectFork(l1.forkId);
+    assertEq(l1.chainSelector, 16015286601757825753);
+    assertEq(address(l1.token), 0xc4bF5CbDaBE595361438F8c6a187bDc330539c60);
+    assertEq(l1.token.balanceOf(alice), 1000e18);
+    assertEq(ITypeAndVersion(address(l1.router)).typeAndVersion(), "Router 1.2.0");
+    assertEq(ITypeAndVersion(l1.proxyPool).typeAndVersion(), "LockReleaseTokenPoolAndProxy 1.5.0");
+    assertEq(l1.EVM2EVMOnRamp1_2.typeAndVersion(), "EVM2EVMOnRamp 1.2.0");
+    assertEq(l1.EVM2EVMOnRamp1_5.typeAndVersion(), "EVM2EVMOnRamp 1.5.0");
+    assertEq(l1.EVM2EVMOffRamp1_2.typeAndVersion(), "EVM2EVMOffRamp 1.2.0");
+    assertEq(l1.EVM2EVMOffRamp1_5.typeAndVersion(), "EVM2EVMOffRamp 1.5.0");
+    assertTrue(l1.router.isOffRamp(l2.chainSelector, address(l1.EVM2EVMOffRamp1_2)));
+    assertTrue(l1.router.isOffRamp(l2.chainSelector, address(l1.EVM2EVMOffRamp1_5)));
+
+    vm.selectFork(l2.forkId);
+    assertEq(l2.chainSelector, 3478487238524512106);
+    assertEq(address(l2.token), 0xb13Cfa6f8B2Eed2C37fB00fF0c1A59807C585810);
+    assertEq(l2.token.balanceOf(alice), 1000e18);
+    assertEq(ITypeAndVersion(address(l2.router)).typeAndVersion(), "Router 1.2.0");
+    assertEq(ITypeAndVersion(l2.proxyPool).typeAndVersion(), "BurnMintTokenPoolAndProxy 1.5.0");
+    assertEq(l2.EVM2EVMOnRamp1_2.typeAndVersion(), "EVM2EVMOnRamp 1.2.0");
+    assertEq(l2.EVM2EVMOnRamp1_5.typeAndVersion(), "EVM2EVMOnRamp 1.5.0");
+    assertEq(l2.EVM2EVMOffRamp1_2.typeAndVersion(), "EVM2EVMOffRamp 1.2.0");
+    assertEq(l2.EVM2EVMOffRamp1_5.typeAndVersion(), "EVM2EVMOffRamp 1.5.0");
+    assertTrue(l2.router.isOffRamp(l1.chainSelector, address(l2.EVM2EVMOffRamp1_2)));
+    assertTrue(l2.router.isOffRamp(l1.chainSelector, address(l2.EVM2EVMOffRamp1_5)));
+
+    _label();
+  }
+
+  function _generateMessage(
+    address receiver,
+    uint256 tokenAmountsLength
+  ) internal pure returns (Client.EVM2AnyMessage memory) {
+    return
+      Client.EVM2AnyMessage({
+        receiver: abi.encode(receiver),
+        data: "",
+        tokenAmounts: new Client.EVMTokenAmount[](tokenAmountsLength),
+        feeToken: address(0),
+        extraArgs: Client._argsToBytes(Client.EVMExtraArgsV1({gasLimit: 0}))
+      });
+  }
+
+  function _messageToEvent(
+    Client.EVM2AnyMessage memory message,
+    address onRamp,
+    uint256 feeTokenAmount,
+    address originalSender,
+    bool isL1
+  ) public view returns (Internal.EVM2EVMMessage memory) {
+    // Slicing is only available for calldata. So we have to build a new bytes array.
+    bytes memory args = new bytes(message.extraArgs.length - 4);
+    for (uint256 i = 4; i < message.extraArgs.length; ++i) {
+      args[i - 4] = message.extraArgs[i];
+    }
+    Client.EVMExtraArgsV1 memory extraArgs = abi.decode(args, (Client.EVMExtraArgsV1));
+    Internal.EVM2EVMMessage memory messageEvent = Internal.EVM2EVMMessage({
+      sequenceNumber: IEVM2AnyOnRamp(onRamp).getExpectedNextSequenceNumber(),
+      feeTokenAmount: feeTokenAmount,
+      sender: originalSender,
+      nonce: IEVM2AnyOnRamp(onRamp).getSenderNonce(originalSender) + 1,
+      gasLimit: extraArgs.gasLimit,
+      strict: false,
+      sourceChainSelector: isL1 ? l1.chainSelector : l2.chainSelector,
+      receiver: abi.decode(message.receiver, (address)),
+      data: message.data,
+      tokenAmounts: message.tokenAmounts,
+      sourceTokenData: new bytes[](message.tokenAmounts.length),
+      feeToken: isL1 ? l1.router.getWrappedNative() : l2.router.getWrappedNative(),
+      messageId: ""
+    });
+
+    if (_hasMigrated(isL1, onRamp)) {
+      for (uint256 i; i < message.tokenAmounts.length; ++i) {
+        // change introduced in 1.5 upgrade
+        messageEvent.sourceTokenData[i] = abi.encode(
+          SourceTokenData({
+            sourcePoolAddress: abi.encode(isL1 ? l1.proxyPool : l2.proxyPool),
+            destTokenAddress: abi.encode(address(isL1 ? l2.token : l1.token)),
+            extraData: "",
+            destGasAmount: _getDestGasAmount(onRamp, message.tokenAmounts[i].token)
+          })
+        );
+      }
+    }
+
+    messageEvent.messageId = Internal._hash(messageEvent, isL1 ? l1.metadataHash : l2.metadataHash);
+    return messageEvent;
+  }
+
+  function _getDestGasAmount(address onRamp, address token) internal view returns (uint32) {
+    IEVM2EVMOnRamp_1_5.TokenTransferFeeConfig memory config = IEVM2EVMOnRamp_1_5(onRamp).getTokenTransferFeeConfig(
+      token
+    );
+    return
+      config.isEnabled
+        ? config.destGasOverhead
+        : IEVM2EVMOnRamp_1_5(onRamp).getDynamicConfig().defaultTokenDestGasOverhead;
+  }
+
+  function _hasMigrated(bool isL1, address onRamp) internal view returns (bool) {
+    return isL1 ? onRamp == address(l1.EVM2EVMOnRamp1_5) : onRamp == address(l2.EVM2EVMOnRamp1_5);
+  }
+
+  function _generateMetadataHash(uint64 sourceChainSelector, IEVM2AnyOnRamp onRamp) internal view returns (bytes32) {
+    uint64 destChainSelector = sourceChainSelector == l1.chainSelector ? l2.chainSelector : l1.chainSelector;
+    return
+      keccak256(abi.encode(Internal.EVM_2_EVM_MESSAGE_HASH, sourceChainSelector, destChainSelector, address(onRamp)));
+  }
+
+  function _label() internal {
+    vm.label(address(l1.tokenPool), "l1.tokenPool");
+    vm.label(address(l1.token), "l1.token");
+    vm.label(address(l1.router), "l1.router");
+    vm.label(address(l1.proxyPool), "l1.proxyPool");
+    vm.label(address(l1.EVM2EVMOnRamp1_2), "l1.EVM2EVMOnRamp1_2");
+    vm.label(address(l1.EVM2EVMOnRamp1_5), "l1.EVM2EVMOnRamp1_5");
+    vm.label(address(l1.EVM2EVMOffRamp1_2), "l1.EVM2EVMOffRamp1_2");
+    vm.label(address(l1.EVM2EVMOffRamp1_5), "l1.EVM2EVMOffRamp1_5");
+
+    vm.label(address(l2.tokenPool), "l2.tokenPool");
+    vm.label(address(l2.token), "l2.token");
+    vm.label(address(l2.router), "l2.router");
+    vm.label(address(l2.proxyPool), "l2.proxyPool");
+    vm.label(address(l2.EVM2EVMOnRamp1_2), "l2.EVM2EVMOnRamp1_2");
+    vm.label(address(l2.EVM2EVMOnRamp1_5), "l2.EVM2EVMOnRamp1_5");
+    vm.label(address(l2.EVM2EVMOffRamp1_2), "l2.EVM2EVMOffRamp1_2");
+    vm.label(address(l2.EVM2EVMOffRamp1_5), "l2.EVM2EVMOffRamp1_5");
+  }
+}
+
+contract ForkPoolAfterMigration is ForkBase {
+  function setUp() public override {
+    super.setUp();
+  }
+
+  /// @dev Tests current version of token pools do not work with legacy on-ramps post 1.5 CCIP Migration
+  /// Only lockOrBurn is incompatible post migration since the new proxyPool becomes a 'wrapped' router
+  /// for the existing token pool, releaseOrMint is still compatible with legacy on-ramps
+  /// see more: https://github.com/smartcontractkit/ccip/blob/11c275959902783a3c4eaddbfaa5ce5f8707e01f/contracts/src/v0.8/ccip/test/legacy/TokenPoolAndProxy.t.sol#L130-L192
+  function testSendViaLegacyRouterReverts() public {
+    uint256 amount = 10e18;
+    // generate lockOrBurn message for lockRelease token pool on L1
+    Client.EVM2AnyMessage memory message = _generateMessage(alice, 1);
+    message.tokenAmounts[0] = Client.EVMTokenAmount({token: address(l1.token), amount: amount});
+
+    vm.selectFork(l1.forkId);
+    uint256 feeTokenAmount = l1.router.getFee(l2.chainSelector, message);
+
+    // validate send reverts with onRamp caller as proxyPool
+    vm.prank(alice);
+    vm.expectRevert(abi.encodeWithSelector(CallerIsNotARampOnRouter.selector, l1.proxyPool));
+    l1.router.ccipSend{value: feeTokenAmount}(l2.chainSelector, message);
+
+    vm.selectFork(l2.forkId);
+    // modify generated lockOrBurn message for burnMint tokenPool on L2
+    message.tokenAmounts[0].token = address(l2.token);
+    feeTokenAmount = l2.router.getFee(l1.chainSelector, message);
+
+    // validate send reverts with onRamp caller as proxyPool
+    vm.prank(alice);
+    vm.expectRevert(abi.encodeWithSelector(CallerIsNotARampOnRouter.selector, l2.proxyPool));
+    l2.router.ccipSend{value: feeTokenAmount}(l1.chainSelector, message);
+  }
+}
+
+contract ForkPoolBeforeMigration is ForkBase {
+  uint256 internal constant BLOCK_BEFORE_MIGRATION_L1 = 6673089;
+  uint256 internal constant BLOCK_BEFORE_MIGRATION_L2 = 79570677;
+
+  function setUp() public override {
+    l1.forkId = vm.createFork(vm.rpcUrl("sepolia"), BLOCK_BEFORE_MIGRATION_L1);
+    l2.forkId = vm.createFork(vm.rpcUrl("arb_sepolia"), BLOCK_BEFORE_MIGRATION_L2);
+
+    vm.selectFork(l1.forkId);
+    l1.tokenPool = UpgradeableLockReleaseTokenPool_Sepolia(0x7768248E1Ff75612c18324bad06bb393c1206980);
+    l1.router = IRouter(l1.tokenPool.getRouter());
+    l2.chainSelector = l1.tokenPool.getSupportedChains()[0];
+    l1.token = l1.tokenPool.getToken();
+    l1.EVM2EVMOnRamp1_2 = IEVM2EVMOnRamp_1_2(l1.router.getOnRamp(l2.chainSelector));
+    l1.EVM2EVMOffRamp1_2 = IEVM2EVMOffRamp_1_2(0xdb92e73d1D630B5B7aC96840c4df0c591c7Ad23E);
+    vm.prank(alice);
+    l1.token.approve(address(l1.router), type(uint256).max);
+    deal(address(l1.token), alice, 1000e18);
+    deal(alice, 1000e18);
+
+    vm.selectFork(l2.forkId);
+    l2.tokenPool = UpgradeableBurnMintTokenPool_ArbSepolia(0x3eC2b6F818B72442fc36561e9F930DD2b60957D2);
+    l2.router = IRouter(l2.tokenPool.getRouter());
+    l1.chainSelector = l2.tokenPool.getSupportedChains()[0];
+    l2.token = l2.tokenPool.getToken();
+    l2.EVM2EVMOnRamp1_2 = IEVM2EVMOnRamp_1_2(l2.router.getOnRamp(l1.chainSelector));
+    l2.EVM2EVMOffRamp1_2 = IEVM2EVMOffRamp_1_2(0xFf5e1c597c5DFfC896Ab8c7b9d876D513518c4b7);
+    vm.prank(alice);
+    l2.token.approve(address(l2.router), type(uint256).max);
+    deal(address(l2.token), alice, 1000e18);
+    deal(alice, 1000e18);
+
+    vm.selectFork(l1.forkId);
+    assertEq(l1.chainSelector, 16015286601757825753);
+    assertEq(address(l1.token), 0xc4bF5CbDaBE595361438F8c6a187bDc330539c60);
+    assertEq(ITypeAndVersion(address(l1.router)).typeAndVersion(), "Router 1.2.0");
+    assertEq(ITypeAndVersion(address(l1.EVM2EVMOnRamp1_2)).typeAndVersion(), "EVM2EVMOnRamp 1.2.0");
+    assertEq(l1.EVM2EVMOffRamp1_2.typeAndVersion(), "EVM2EVMOffRamp 1.2.0");
+    assertTrue(l1.router.isOffRamp(l2.chainSelector, address(l1.EVM2EVMOffRamp1_2)));
+    // assert only one off ramp is set
+    IRouter.OffRamp[] memory offRamps = l1.router.getOffRamps();
+    for (uint256 i; i < offRamps.length; ++i) {
+      if (offRamps[i].sourceChainSelector == l2.chainSelector) {
+        assertEq(address(l1.EVM2EVMOffRamp1_2), offRamps[i].offRamp);
+      }
+    }
+
+    vm.selectFork(l2.forkId);
+    assertEq(l2.chainSelector, 3478487238524512106);
+    assertEq(address(l2.token), 0xb13Cfa6f8B2Eed2C37fB00fF0c1A59807C585810);
+    assertEq(ITypeAndVersion(address(l2.router)).typeAndVersion(), "Router 1.2.0");
+    assertEq(ITypeAndVersion(address(l2.EVM2EVMOnRamp1_2)).typeAndVersion(), "EVM2EVMOnRamp 1.2.0");
+    assertEq(l2.EVM2EVMOffRamp1_2.typeAndVersion(), "EVM2EVMOffRamp 1.2.0");
+    assertTrue(l2.router.isOffRamp(l1.chainSelector, address(l2.EVM2EVMOffRamp1_2)));
+    // assert only one off ramp is set
+    offRamps = l2.router.getOffRamps();
+    for (uint256 i; i < offRamps.length; ++i) {
+      if (offRamps[i].sourceChainSelector == l1.chainSelector) {
+        assertEq(address(l2.EVM2EVMOffRamp1_2), offRamps[i].offRamp);
+      }
+    }
+  }
+
+  function testSendViaRouter() public {
+    uint256 amount = 10e18;
+    Client.EVM2AnyMessage memory message = _generateMessage(alice, 1);
+    message.tokenAmounts[0] = Client.EVMTokenAmount({token: address(l1.token), amount: amount});
+
+    {
+      vm.selectFork(l1.forkId);
+      uint256 feeTokenAmount = l1.router.getFee(l2.chainSelector, message);
+
+      vm.expectEmit();
+      emit Locked(address(l1.EVM2EVMOnRamp1_2), amount);
+      vm.prank(alice);
+      l1.router.ccipSend{value: feeTokenAmount}(l2.chainSelector, message);
+    }
+    {
+      vm.selectFork(l2.forkId);
+      message.tokenAmounts[0].token = address(l2.token);
+      uint256 feeTokenAmount = l2.router.getFee(l1.chainSelector, message);
+
+      vm.expectEmit();
+      emit Burned(address(l2.EVM2EVMOnRamp1_2), amount);
+      vm.prank(alice);
+      l2.router.ccipSend{value: feeTokenAmount}(l1.chainSelector, message);
+    }
+  }
+
+  function testLockOrBurnVia1_2OnRamp() public {
+    uint256 amount = 10e18;
+    {
+      vm.selectFork(l1.forkId);
+
+      vm.expectEmit();
+      emit Locked(address(l1.EVM2EVMOnRamp1_2), amount);
+      vm.prank(address(l1.EVM2EVMOnRamp1_2));
+      l1.tokenPool.lockOrBurn(alice, abi.encode(alice), amount, l2.chainSelector, "");
+    }
+    {
+      vm.selectFork(l2.forkId);
+      // router is responsible for transferring liquidity, so we mock router.token.transferFrom(user, tokenPool)
+      deal(address(l2.token), address(l2.tokenPool), amount);
+
+      vm.expectEmit();
+      emit Burned(address(l2.EVM2EVMOnRamp1_2), amount);
+      vm.prank(address(l2.EVM2EVMOnRamp1_2));
+      l2.tokenPool.lockOrBurn(alice, abi.encode(alice), amount, l1.chainSelector, "");
+    }
+  }
+
+  function testReleaseOrMintVia1_2OffRamp() public {
+    uint256 amount = 10e18;
+    Client.EVM2AnyMessage memory message = _generateMessage(alice, 1);
+
+    // off ramp on L1
+    {
+      // build message
+      vm.selectFork(l2.forkId);
+      message.tokenAmounts[0] = Client.EVMTokenAmount({token: address(l2.token), amount: amount});
+      uint256 feeTokenAmount = l2.router.getFee(l1.chainSelector, message);
+      Internal.EVM2EVMMessage memory eventArg = _messageToEvent(
+        message,
+        address(l2.EVM2EVMOnRamp1_2),
+        feeTokenAmount,
+        alice,
+        false
+      );
+
+      // test off ramp
+      vm.selectFork(l1.forkId);
+
+      uint256 balanceBefore = l1.token.balanceOf(alice);
+
+      vm.expectEmit(address(l1.tokenPool));
+      emit Released(address(l1.EVM2EVMOffRamp1_2), alice, amount);
+      vm.prank(address(l1.EVM2EVMOffRamp1_2));
+      l1.EVM2EVMOffRamp1_2.executeSingleMessage(eventArg, new bytes[](message.tokenAmounts.length));
+
+      assertEq(l1.token.balanceOf(alice), balanceBefore + amount);
+    }
+
+    // off ramp on L2
+    {
+      // build message
+      vm.selectFork(l1.forkId);
+      message.tokenAmounts[0] = Client.EVMTokenAmount({token: address(l1.token), amount: amount});
+      uint256 feeTokenAmount = l1.router.getFee(l2.chainSelector, message);
+      Internal.EVM2EVMMessage memory eventArg = _messageToEvent(
+        message,
+        address(l1.EVM2EVMOnRamp1_2),
+        feeTokenAmount,
+        alice,
+        true
+      );
+
+      // test off ramp
+      vm.selectFork(l2.forkId);
+
+      uint256 balanceBefore = l2.token.balanceOf(alice);
+
+      vm.expectEmit(address(l2.tokenPool));
+      emit Minted(address(l2.EVM2EVMOffRamp1_2), alice, amount);
+      vm.prank(address(l2.EVM2EVMOffRamp1_2));
+      l2.EVM2EVMOffRamp1_2.executeSingleMessage(eventArg, new bytes[](message.tokenAmounts.length));
+
+      assertEq(l2.token.balanceOf(alice), balanceBefore + amount);
+    }
+  }
+}
diff --git a/contracts/src/v0.8/ccip/test/pools/GHO/fork/GhoTokenPoolMigrate1_4To1_5/LegacyTestnetTokenPools/UpgradeableBurnMintTokenPool_ArbSepolia.sol b/contracts/src/v0.8/ccip/test/pools/GHO/fork/GhoTokenPoolMigrate1_4To1_5/LegacyTestnetTokenPools/UpgradeableBurnMintTokenPool_ArbSepolia.sol
new file mode 100644
index 0000000000..3fbf062b63
--- /dev/null
+++ b/contracts/src/v0.8/ccip/test/pools/GHO/fork/GhoTokenPoolMigrate1_4To1_5/LegacyTestnetTokenPools/UpgradeableBurnMintTokenPool_ArbSepolia.sol
@@ -0,0 +1,68 @@
+// SPDX-License-Identifier: BUSL-1.1
+pragma solidity ^0.8.0;
+
+import {ITypeAndVersion} from "../../../../../../../shared/interfaces/ITypeAndVersion.sol";
+import {IBurnMintERC20} from "../../../../../../../shared/token/ERC20/IBurnMintERC20.sol";
+import {UpgradeableTokenPool} from "../../../../../../pools/GHO/UpgradeableTokenPool.sol";
+import {UpgradeableBurnMintTokenPoolAbstract} from "../../../../../../pools/GHO/UpgradeableBurnMintTokenPoolAbstract.sol";
+import {IRouter} from "../../../../../../interfaces/IRouter.sol";
+import {VersionedInitializable} from "./VersionedInitializable.sol";
+
+/// @title UpgradeableBurnMintTokenPool_ArbSepolia
+/// @author Aave Labs
+/// @notice Upgradeable version of Chainlink's CCIP BurnMintTokenPool
+/// @dev Contract adaptations:
+/// - Implementation of VersionedInitializable to allow upgrades
+/// - Move of allowlist and router definition to initialization stage
+contract UpgradeableBurnMintTokenPool_ArbSepolia is
+  VersionedInitializable,
+  UpgradeableBurnMintTokenPoolAbstract,
+  ITypeAndVersion
+{
+  string public constant override typeAndVersion = "BurnMintTokenPool 1.4.0";
+
+  /// @dev Constructor
+  /// @param token The bridgeable token that is managed by this pool.
+  /// @param armProxy The address of the arm proxy
+  /// @param allowlistEnabled True if pool is set to access-controlled mode, false otherwise
+  constructor(
+    address token,
+    address armProxy,
+    bool allowlistEnabled
+  ) UpgradeableTokenPool(IBurnMintERC20(token), armProxy, allowlistEnabled) {}
+
+  /// @dev Initializer
+  /// @dev The address passed as `owner` must accept ownership after initialization.
+  /// @dev The `allowlist` is only effective if pool is set to access-controlled mode
+  /// @param owner The address of the owner
+  /// @param allowlist A set of addresses allowed to trigger lockOrBurn as original senders
+  /// @param router The address of the router
+  function initialize(address owner, address[] memory allowlist, address router) public virtual initializer {
+    if (owner == address(0)) revert ZeroAddressNotAllowed();
+    if (router == address(0)) revert ZeroAddressNotAllowed();
+    _transferOwnership(owner);
+
+    s_router = IRouter(router);
+
+    // Pool can be set as permissioned or permissionless at deployment time only to save hot-path gas.
+    if (i_allowlistEnabled) {
+      _applyAllowListUpdates(new address[](0), allowlist);
+    }
+  }
+
+  /// @inheritdoc UpgradeableBurnMintTokenPoolAbstract
+  function _burn(uint256 amount) internal virtual override {
+    IBurnMintERC20(address(i_token)).burn(amount);
+  }
+
+  /// @notice Returns the revision number
+  /// @return The revision number
+  function REVISION() public pure virtual returns (uint256) {
+    return 1;
+  }
+
+  /// @inheritdoc VersionedInitializable
+  function getRevision() internal pure virtual override returns (uint256) {
+    return REVISION();
+  }
+}
diff --git a/contracts/src/v0.8/ccip/test/pools/GHO/fork/GhoTokenPoolMigrate1_4To1_5/LegacyTestnetTokenPools/UpgradeableLockReleaseTokenPool_Sepolia.sol b/contracts/src/v0.8/ccip/test/pools/GHO/fork/GhoTokenPoolMigrate1_4To1_5/LegacyTestnetTokenPools/UpgradeableLockReleaseTokenPool_Sepolia.sol
new file mode 100644
index 0000000000..748ebd7d84
--- /dev/null
+++ b/contracts/src/v0.8/ccip/test/pools/GHO/fork/GhoTokenPoolMigrate1_4To1_5/LegacyTestnetTokenPools/UpgradeableLockReleaseTokenPool_Sepolia.sol
@@ -0,0 +1,278 @@
+// SPDX-License-Identifier: BUSL-1.1
+pragma solidity ^0.8.0;
+
+import {ITypeAndVersion} from "../../../../../../../shared/interfaces/ITypeAndVersion.sol";
+
+import {ILiquidityContainer} from "../../../../../../../rebalancer/interfaces/ILiquidityContainer.sol";
+
+import {UpgradeableTokenPool} from "../../../../../../pools/GHO/UpgradeableTokenPool.sol";
+import {RateLimiter} from "../../../../../../libraries/RateLimiter.sol";
+
+import {IERC20} from "../../../../../../../vendor/openzeppelin-solidity/v4.8.3/contracts/token/ERC20/IERC20.sol";
+import {SafeERC20} from "../../../../../../../vendor/openzeppelin-solidity/v4.8.3/contracts/token/ERC20/utils/SafeERC20.sol";
+
+import {IRouter} from "../../../../../../interfaces/IRouter.sol";
+import {VersionedInitializable} from "./VersionedInitializable.sol";
+
+/// @title UpgradeableLockReleaseTokenPool_Sepolia
+/// @author Aave Labs
+/// @notice Upgradeable version of Chainlink's CCIP LockReleaseTokenPool
+/// @dev Contract adaptations:
+/// - Implementation of VersionedInitializable to allow upgrades
+/// - Move of allowlist and router definition to initialization stage
+/// - Addition of a bridge limit to regulate the maximum amount of tokens that can be transferred out (burned/locked)
+contract UpgradeableLockReleaseTokenPool_Sepolia is
+  VersionedInitializable,
+  UpgradeableTokenPool,
+  ILiquidityContainer,
+  ITypeAndVersion
+{
+  using SafeERC20 for IERC20;
+
+  error InsufficientLiquidity();
+  error LiquidityNotAccepted();
+  error Unauthorized(address caller);
+
+  error BridgeLimitExceeded(uint256 bridgeLimit);
+  error NotEnoughBridgedAmount();
+  event BridgeLimitUpdated(uint256 oldBridgeLimit, uint256 newBridgeLimit);
+
+  string public constant override typeAndVersion = "LockReleaseTokenPool 1.4.0";
+
+  /// @dev The unique lock release pool flag to signal through EIP 165.
+  bytes4 private constant LOCK_RELEASE_INTERFACE_ID = bytes4(keccak256("LockReleaseTokenPool"));
+
+  /// @dev Whether or not the pool accepts liquidity.
+  /// External liquidity is not required when there is one canonical token deployed to a chain,
+  /// and CCIP is facilitating mint/burn on all the other chains, in which case the invariant
+  /// balanceOf(pool) on home chain == sum(totalSupply(mint/burn "wrapped" token) on all remote chains) should always hold
+  bool internal immutable i_acceptLiquidity;
+  /// @notice The address of the rebalancer.
+  address internal s_rebalancer;
+  /// @notice The address of the rate limiter admin.
+  /// @dev Can be address(0) if none is configured.
+  address internal s_rateLimitAdmin;
+
+  /// @notice Maximum amount of tokens that can be bridged to other chains
+  uint256 private s_bridgeLimit;
+  /// @notice Amount of tokens bridged (transferred out)
+  /// @dev Must always be equal to or below the bridge limit
+  uint256 private s_currentBridged;
+  /// @notice The address of the bridge limit admin.
+  /// @dev Can be address(0) if none is configured.
+  address internal s_bridgeLimitAdmin;
+
+  /// @dev Constructor
+  /// @param token The bridgeable token that is managed by this pool.
+  /// @param armProxy The address of the arm proxy
+  /// @param allowlistEnabled True if pool is set to access-controlled mode, false otherwise
+  /// @param acceptLiquidity True if the pool accepts liquidity, false otherwise
+  constructor(
+    address token,
+    address armProxy,
+    bool allowlistEnabled,
+    bool acceptLiquidity
+  ) UpgradeableTokenPool(IERC20(token), armProxy, allowlistEnabled) {
+    i_acceptLiquidity = acceptLiquidity;
+  }
+
+  /// @dev Initializer
+  /// @dev The address passed as `owner` must accept ownership after initialization.
+  /// @dev The `allowlist` is only effective if pool is set to access-controlled mode
+  /// @param owner The address of the owner
+  /// @param allowlist A set of addresses allowed to trigger lockOrBurn as original senders
+  /// @param router The address of the router
+  /// @param bridgeLimit The maximum amount of tokens that can be bridged to other chains
+  function initialize(
+    address owner,
+    address[] memory allowlist,
+    address router,
+    uint256 bridgeLimit
+  ) public virtual initializer {
+    if (owner == address(0)) revert ZeroAddressNotAllowed();
+    if (router == address(0)) revert ZeroAddressNotAllowed();
+    _transferOwnership(owner);
+
+    s_router = IRouter(router);
+
+    // Pool can be set as permissioned or permissionless at deployment time only to save hot-path gas.
+    if (i_allowlistEnabled) {
+      _applyAllowListUpdates(new address[](0), allowlist);
+    }
+    s_bridgeLimit = bridgeLimit;
+  }
+
+  /// @notice Locks the token in the pool
+  /// @param amount Amount to lock
+  /// @dev The whenHealthy check is important to ensure that even if a ramp is compromised
+  /// we're able to stop token movement via ARM.
+  function lockOrBurn(
+    address originalSender,
+    bytes calldata,
+    uint256 amount,
+    uint64 remoteChainSelector,
+    bytes calldata
+  )
+    external
+    virtual
+    override
+    onlyOnRamp(remoteChainSelector)
+    checkAllowList(originalSender)
+    whenHealthy
+    returns (bytes memory)
+  {
+    // Increase bridged amount because tokens are leaving the source chain
+    if ((s_currentBridged += amount) > s_bridgeLimit) revert BridgeLimitExceeded(s_bridgeLimit);
+
+    _consumeOutboundRateLimit(remoteChainSelector, amount);
+    emit Locked(msg.sender, amount);
+    return "";
+  }
+
+  /// @notice Release tokens from the pool to the recipient
+  /// @param receiver Recipient address
+  /// @param amount Amount to release
+  /// @dev The whenHealthy check is important to ensure that even if a ramp is compromised
+  /// we're able to stop token movement via ARM.
+  function releaseOrMint(
+    bytes memory,
+    address receiver,
+    uint256 amount,
+    uint64 remoteChainSelector,
+    bytes memory
+  ) external virtual override onlyOffRamp(remoteChainSelector) whenHealthy {
+    // This should never occur. Amount should never exceed the current bridged amount
+    if (amount > s_currentBridged) revert NotEnoughBridgedAmount();
+    // Reduce bridged amount because tokens are back to source chain
+    s_currentBridged -= amount;
+
+    _consumeInboundRateLimit(remoteChainSelector, amount);
+    getToken().safeTransfer(receiver, amount);
+    emit Released(msg.sender, receiver, amount);
+  }
+
+  /// @notice returns the lock release interface flag used for EIP165 identification.
+  function getLockReleaseInterfaceId() public pure returns (bytes4) {
+    return LOCK_RELEASE_INTERFACE_ID;
+  }
+
+  // @inheritdoc IERC165
+  function supportsInterface(bytes4 interfaceId) public pure virtual override returns (bool) {
+    return
+      interfaceId == LOCK_RELEASE_INTERFACE_ID ||
+      interfaceId == type(ILiquidityContainer).interfaceId ||
+      super.supportsInterface(interfaceId);
+  }
+
+  /// @notice Gets Rebalancer, can be address(0) if none is configured.
+  /// @return The current liquidity manager.
+  function getRebalancer() external view returns (address) {
+    return s_rebalancer;
+  }
+
+  /// @notice Sets the Rebalancer address.
+  /// @dev Only callable by the owner.
+  function setRebalancer(address rebalancer) external onlyOwner {
+    s_rebalancer = rebalancer;
+  }
+
+  /// @notice Sets the rate limiter admin address.
+  /// @dev Only callable by the owner.
+  /// @param rateLimitAdmin The new rate limiter admin address.
+  function setRateLimitAdmin(address rateLimitAdmin) external onlyOwner {
+    s_rateLimitAdmin = rateLimitAdmin;
+  }
+
+  /// @notice Sets the bridge limit, the maximum amount of tokens that can be bridged out
+  /// @dev Only callable by the owner or the bridge limit admin.
+  /// @dev Bridge limit changes should be carefully managed, specially when reducing below the current bridged amount
+  /// @param newBridgeLimit The new bridge limit
+  function setBridgeLimit(uint256 newBridgeLimit) external {
+    if (msg.sender != s_bridgeLimitAdmin && msg.sender != owner()) revert Unauthorized(msg.sender);
+    uint256 oldBridgeLimit = s_bridgeLimit;
+    s_bridgeLimit = newBridgeLimit;
+    emit BridgeLimitUpdated(oldBridgeLimit, newBridgeLimit);
+  }
+
+  /// @notice Sets the bridge limit admin address.
+  /// @dev Only callable by the owner.
+  /// @param bridgeLimitAdmin The new bridge limit admin address.
+  function setBridgeLimitAdmin(address bridgeLimitAdmin) external onlyOwner {
+    s_bridgeLimitAdmin = bridgeLimitAdmin;
+  }
+
+  /// @notice Gets the bridge limit
+  /// @return The maximum amount of tokens that can be transferred out to other chains
+  function getBridgeLimit() external view virtual returns (uint256) {
+    return s_bridgeLimit;
+  }
+
+  /// @notice Gets the current bridged amount to other chains
+  /// @return The amount of tokens transferred out to other chains
+  function getCurrentBridgedAmount() external view virtual returns (uint256) {
+    return s_currentBridged;
+  }
+
+  /// @notice Gets the rate limiter admin address.
+  function getRateLimitAdmin() external view returns (address) {
+    return s_rateLimitAdmin;
+  }
+
+  /// @notice Gets the bridge limiter admin address.
+  function getBridgeLimitAdmin() external view returns (address) {
+    return s_bridgeLimitAdmin;
+  }
+
+  /// @notice Checks if the pool can accept liquidity.
+  /// @return true if the pool can accept liquidity, false otherwise.
+  function canAcceptLiquidity() external view returns (bool) {
+    return i_acceptLiquidity;
+  }
+
+  /// @notice Adds liquidity to the pool. The tokens should be approved first.
+  /// @param amount The amount of liquidity to provide.
+  function provideLiquidity(uint256 amount) external {
+    if (!i_acceptLiquidity) revert LiquidityNotAccepted();
+    if (s_rebalancer != msg.sender) revert Unauthorized(msg.sender);
+
+    i_token.safeTransferFrom(msg.sender, address(this), amount);
+    emit LiquidityAdded(msg.sender, amount);
+  }
+
+  /// @notice Removed liquidity to the pool. The tokens will be sent to msg.sender.
+  /// @param amount The amount of liquidity to remove.
+  function withdrawLiquidity(uint256 amount) external {
+    if (s_rebalancer != msg.sender) revert Unauthorized(msg.sender);
+
+    if (i_token.balanceOf(address(this)) < amount) revert InsufficientLiquidity();
+    i_token.safeTransfer(msg.sender, amount);
+    emit LiquidityRemoved(msg.sender, amount);
+  }
+
+  /// @notice Sets the rate limiter admin address.
+  /// @dev Only callable by the owner or the rate limiter admin. NOTE: overwrites the normal
+  /// onlyAdmin check in the base implementation to also allow the rate limiter admin.
+  /// @param remoteChainSelector The remote chain selector for which the rate limits apply.
+  /// @param outboundConfig The new outbound rate limiter config.
+  /// @param inboundConfig The new inbound rate limiter config.
+  function setChainRateLimiterConfig(
+    uint64 remoteChainSelector,
+    RateLimiter.Config memory outboundConfig,
+    RateLimiter.Config memory inboundConfig
+  ) external override {
+    if (msg.sender != s_rateLimitAdmin && msg.sender != owner()) revert Unauthorized(msg.sender);
+
+    _setRateLimitConfig(remoteChainSelector, outboundConfig, inboundConfig);
+  }
+
+  /// @notice Returns the revision number
+  /// @return The revision number
+  function REVISION() public pure virtual returns (uint256) {
+    return 1;
+  }
+
+  /// @inheritdoc VersionedInitializable
+  function getRevision() internal pure virtual override returns (uint256) {
+    return REVISION();
+  }
+}
diff --git a/contracts/src/v0.8/ccip/test/pools/GHO/fork/GhoTokenPoolMigrate1_4To1_5/LegacyTestnetTokenPools/VersionedInitializable.sol b/contracts/src/v0.8/ccip/test/pools/GHO/fork/GhoTokenPoolMigrate1_4To1_5/LegacyTestnetTokenPools/VersionedInitializable.sol
new file mode 100644
index 0000000000..b9fb054fa0
--- /dev/null
+++ b/contracts/src/v0.8/ccip/test/pools/GHO/fork/GhoTokenPoolMigrate1_4To1_5/LegacyTestnetTokenPools/VersionedInitializable.sol
@@ -0,0 +1,77 @@
+// SPDX-License-Identifier: AGPL-3.0
+pragma solidity ^0.8.0;
+
+/**
+ * @title VersionedInitializable
+ * @author Aave, inspired by the OpenZeppelin Initializable contract
+ * @notice Helper contract to implement initializer functions. To use it, replace
+ * the constructor with a function that has the `initializer` modifier.
+ * @dev WARNING: Unlike constructors, initializer functions must be manually
+ * invoked. This applies both to deploying an Initializable contract, as well
+ * as extending an Initializable contract via inheritance.
+ * WARNING: When used with inheritance, manual care must be taken to not invoke
+ * a parent initializer twice, or ensure that all initializers are idempotent,
+ * because this is not dealt with automatically as with constructors.
+ */
+abstract contract VersionedInitializable {
+  /**
+   * @dev Indicates that the contract has been initialized.
+   */
+  uint256 private lastInitializedRevision = 0;
+
+  /**
+   * @dev Indicates that the contract is in the process of being initialized.
+   */
+  bool private initializing;
+
+  /**
+   * @dev Modifier to use in the initializer function of a contract.
+   */
+  modifier initializer() {
+    uint256 revision = getRevision();
+    require(
+      initializing || isConstructor() || revision > lastInitializedRevision,
+      "Contract instance has already been initialized"
+    );
+
+    bool isTopLevelCall = !initializing;
+    if (isTopLevelCall) {
+      initializing = true;
+      lastInitializedRevision = revision;
+    }
+
+    _;
+
+    if (isTopLevelCall) {
+      initializing = false;
+    }
+  }
+
+  /**
+   * @notice Returns the revision number of the contract
+   * @dev Needs to be defined in the inherited class as a constant.
+   * @return The revision number
+   */
+  function getRevision() internal pure virtual returns (uint256);
+
+  /**
+   * @notice Returns true if and only if the function is running in the constructor
+   * @return True if the function is running in the constructor
+   */
+  function isConstructor() private view returns (bool) {
+    // extcodesize checks the size of the code stored in an address, and
+    // address returns the current address. Since the code is still not
+    // deployed when running a constructor, any checks on its code size will
+    // yield zero, making it an effective way to detect if a contract is
+    // under construction or not.
+    uint256 cs;
+    //solium-disable-next-line
+    assembly {
+      cs := extcodesize(address())
+    }
+    return cs == 0;
+  }
+
+  // Reserved storage space to allow for layout changes in the future.
+  uint256[50] private ______gap;
+}
diff --git a/contracts/src/v0.8/ccip/test/pools/GHO/fork/GhoTokenPoolMigrate1_4To1_5/TokenPoolsUpgrade.t.sol b/contracts/src/v0.8/ccip/test/pools/GHO/fork/GhoTokenPoolMigrate1_4To1_5/TokenPoolsUpgrade.t.sol
new file mode 100644
index 0000000000..a649167773
--- /dev/null
+++ b/contracts/src/v0.8/ccip/test/pools/GHO/fork/GhoTokenPoolMigrate1_4To1_5/TokenPoolsUpgrade.t.sol
@@ -0,0 +1,239 @@
+// SPDX-License-Identifier: BUSL-1.1
+pragma solidity 0.8.19;
+
+import {TransparentUpgradeableProxy} from "solidity-utils/contracts/transparent-proxy/TransparentUpgradeableProxy.sol";
+import {ProxyAdmin} from "solidity-utils/contracts/transparent-proxy/ProxyAdmin.sol";
+import {Client} from "../../../../../libraries/Client.sol";
+import {Internal} from "../../../../../libraries/Internal.sol";
+import {ForkBase} from "./ForkBase.t.sol";
+import {UpgradeableLockReleaseTokenPool_Sepolia} from "./LegacyTestnetTokenPools/UpgradeableLockReleaseTokenPool_Sepolia.sol";
+import {UpgradeableBurnMintTokenPool_ArbSepolia} from "./LegacyTestnetTokenPools/UpgradeableBurnMintTokenPool_ArbSepolia.sol";
+
+contract ForkPoolUpgradeAfterMigration is ForkBase {
+  function setUp() public override {
+    super.setUp();
+
+    // #1: deploy new implementation & upgrade token pools
+    vm.selectFork(l1.forkId);
+    _upgradeExistingLockReleaseTokenPool();
+
+    vm.selectFork(l2.forkId);
+    _upgradeExistingBurnMintTokenPool();
+
+    // #2: setProxyPool
+    vm.selectFork(l1.forkId);
+    vm.prank(l1.tokenPool.owner());
+    l1.tokenPool.setProxyPool(l1.proxyPool);
+
+    vm.selectFork(l2.forkId);
+    vm.prank(l2.tokenPool.owner());
+    l2.tokenPool.setProxyPool(l2.proxyPool);
+  }
+
+  function testLockOrBurnViaRouter() public {
+    uint256 amount = 10e18;
+    Client.EVM2AnyMessage memory message = _generateMessage(alice, 1);
+
+    {
+      vm.selectFork(l1.forkId);
+
+      message.tokenAmounts[0] = Client.EVMTokenAmount({token: address(l1.token), amount: amount});
+      uint256 feeTokenAmount = l1.router.getFee(l2.chainSelector, message);
+
+      // router uses 1_5 onRamp
+      assertEq(l1.router.getOnRamp(l2.chainSelector), address(l1.EVM2EVMOnRamp1_5));
+      vm.expectEmit();
+      emit CCIPSendRequested(_messageToEvent(message, address(l1.EVM2EVMOnRamp1_5), feeTokenAmount, alice, true));
+      vm.prank(alice);
+      l1.router.ccipSend{value: feeTokenAmount}(l2.chainSelector, message);
+    }
+
+    {
+      vm.selectFork(l2.forkId);
+
+      message.tokenAmounts[0] = Client.EVMTokenAmount({token: address(l2.token), amount: amount});
+      uint256 feeTokenAmount = l2.router.getFee(l1.chainSelector, message);
+
+      // router uses 1_5 onRamp
+      assertEq(l2.router.getOnRamp(l1.chainSelector), address(l2.EVM2EVMOnRamp1_5));
+      vm.expectEmit();
+      emit CCIPSendRequested(_messageToEvent(message, address(l2.EVM2EVMOnRamp1_5), feeTokenAmount, alice, false));
+      vm.prank(alice);
+      l2.router.ccipSend{value: feeTokenAmount}(l1.chainSelector, message);
+    }
+  }
+
+  function testRevertLockOrBurnVia1_2OnRamp() public {
+    uint256 amount = 10e18;
+    {
+      vm.selectFork(l1.forkId);
+      vm.expectRevert(abi.encodeWithSelector(CallerIsNotARampOnRouter.selector, address(l1.EVM2EVMOnRamp1_2)));
+      vm.prank(address(l1.EVM2EVMOnRamp1_2));
+      l1.tokenPool.lockOrBurn(alice, abi.encode(alice), amount, l2.chainSelector, "");
+    }
+    {
+      vm.selectFork(l2.forkId);
+      vm.expectRevert(abi.encodeWithSelector(CallerIsNotARampOnRouter.selector, address(l2.EVM2EVMOnRamp1_2)));
+      vm.prank(address(l2.EVM2EVMOnRamp1_2));
+      l2.tokenPool.lockOrBurn(alice, abi.encode(alice), amount, l1.chainSelector, "");
+    }
+  }
+
+  function testReleaseOrMintVia1_2OffRamp() public {
+    uint256 amount = 10e18;
+    Client.EVM2AnyMessage memory message = _generateMessage(alice, 1);
+
+    // off ramp on L1
+    {
+      // build message
+      vm.selectFork(l2.forkId);
+      message.tokenAmounts[0] = Client.EVMTokenAmount({token: address(l2.token), amount: amount});
+      uint256 feeTokenAmount = l2.router.getFee(l1.chainSelector, message);
+      Internal.EVM2EVMMessage memory eventArg = _messageToEvent(
+        message,
+        address(l2.EVM2EVMOnRamp1_5),
+        feeTokenAmount,
+        alice,
+        false
+      );
+
+      // test off ramp
+      vm.selectFork(l1.forkId);
+
+      uint256 balanceBefore = l1.token.balanceOf(alice);
+
+      vm.expectEmit(address(l1.tokenPool));
+      emit Released(address(l1.EVM2EVMOffRamp1_2), alice, amount);
+      vm.prank(address(l1.EVM2EVMOffRamp1_2));
+      l1.EVM2EVMOffRamp1_2.executeSingleMessage(eventArg, new bytes[](message.tokenAmounts.length));
+
+      assertEq(l1.token.balanceOf(alice), balanceBefore + amount);
+    }
+
+    // off ramp on L2
+    {
+      // build message
+      vm.selectFork(l1.forkId);
+      message.tokenAmounts[0] = Client.EVMTokenAmount({token: address(l1.token), amount: amount});
+      uint256 feeTokenAmount = l1.router.getFee(l2.chainSelector, message);
+      Internal.EVM2EVMMessage memory eventArg = _messageToEvent(
+        message,
+        address(l1.EVM2EVMOnRamp1_5),
+        feeTokenAmount,
+        alice,
+        true
+      );
+
+      // test off ramp
+      vm.selectFork(l2.forkId);
+
+      uint256 balanceBefore = l2.token.balanceOf(alice);
+
+      vm.expectEmit(address(l2.tokenPool));
+      emit Minted(address(l2.EVM2EVMOffRamp1_2), alice, amount);
+      vm.prank(address(l2.EVM2EVMOffRamp1_2));
+      l2.EVM2EVMOffRamp1_2.executeSingleMessage(eventArg, new bytes[](message.tokenAmounts.length));
+
+      assertEq(l2.token.balanceOf(alice), balanceBefore + amount);
+    }
+  }
+
+  function testReleaseOrMintVia1_5OffRamp() public {
+    uint256 amount = 10e18;
+    Client.EVM2AnyMessage memory message = _generateMessage(alice, 1);
+
+    // off ramp on L1
+    {
+      // build message
+      vm.selectFork(l2.forkId);
+      message.tokenAmounts[0] = Client.EVMTokenAmount({token: address(l2.token), amount: amount});
+      uint256 feeTokenAmount = l2.router.getFee(l1.chainSelector, message);
+      Internal.EVM2EVMMessage memory eventArg = _messageToEvent(
+        message,
+        address(l2.EVM2EVMOnRamp1_5),
+        feeTokenAmount,
+        alice,
+        false
+      );
+
+      // test off ramp
+      vm.selectFork(l1.forkId);
+
+      uint256 balanceBefore = l1.token.balanceOf(alice);
+
+      vm.expectEmit(address(l1.tokenPool));
+      emit Released(address(l1.proxyPool), alice, amount);
+      vm.expectEmit(address(l1.proxyPool));
+      emit Released(address(l1.EVM2EVMOffRamp1_5), alice, amount);
+      vm.prank(address(l1.EVM2EVMOffRamp1_5));
+      l1.EVM2EVMOffRamp1_5.executeSingleMessage(eventArg, new bytes[](message.tokenAmounts.length), new uint32[](0));
+
+      assertEq(l1.token.balanceOf(alice), balanceBefore + amount);
+    }
+
+    // off ramp on L2
+    {
+      // build message
+      vm.selectFork(l1.forkId);
+      message.tokenAmounts[0] = Client.EVMTokenAmount({token: address(l1.token), amount: amount});
+      uint256 feeTokenAmount = l1.router.getFee(l2.chainSelector, message);
+      Internal.EVM2EVMMessage memory eventArg = _messageToEvent(
+        message,
+        address(l1.EVM2EVMOnRamp1_5),
+        feeTokenAmount,
+        alice,
+        true
+      );
+
+      // test off ramp
+      vm.selectFork(l2.forkId);
+
+      uint256 balanceBefore = l2.token.balanceOf(alice);
+
+      vm.expectEmit(address(l2.tokenPool));
+      emit Minted(address(l2.proxyPool), alice, amount);
+      vm.expectEmit(address(l2.proxyPool));
+      emit Minted(address(l2.EVM2EVMOffRamp1_5), alice, amount);
+      vm.prank(address(l2.EVM2EVMOffRamp1_5));
+      l2.EVM2EVMOffRamp1_5.executeSingleMessage(eventArg, new bytes[](message.tokenAmounts.length), new uint32[](0));
+
+      assertEq(l2.token.balanceOf(alice), balanceBefore + amount);
+    }
+  }
+
+  function _upgradeExistingLockReleaseTokenPool() internal {
+    UpgradeableLockReleaseTokenPool_Sepolia poolImpl = new UpgradeableLockReleaseTokenPool_Sepolia(
+      address(l1.token),
+      l1.tokenPool.getArmProxy(),
+      l1.tokenPool.getAllowListEnabled(),
+      l1.tokenPool.canAcceptLiquidity()
+    );
+    _upgradeProxy(TransparentUpgradeableProxy(payable(address(l1.tokenPool))), address(poolImpl));
+  }
+
+  function _upgradeExistingBurnMintTokenPool() internal {
+    UpgradeableBurnMintTokenPool_ArbSepolia poolImpl = new UpgradeableBurnMintTokenPool_ArbSepolia(
+      address(l2.token),
+      l2.tokenPool.getArmProxy(),
+      l2.tokenPool.getAllowListEnabled()
+    );
+    _upgradeProxy(TransparentUpgradeableProxy(payable(address(l2.tokenPool))), address(poolImpl));
+  }
+
+  function _upgradeProxy(TransparentUpgradeableProxy proxy, address impl) private {
+    address proxyAdminAddress = address(
+      uint160(uint256(vm.load(address(proxy), bytes32(uint256(keccak256("eip1967.proxy.admin")) - 1))))
+    );
+    assertNotEq(proxyAdminAddress, address(0), "version mismatch: proxyAdmin");
+    if (proxyAdminAddress.code.length != 0) {
+      ProxyAdmin proxyAdmin = ProxyAdmin(proxyAdminAddress);
+      assertEq(proxyAdmin.getProxyAdmin(proxy), address(proxyAdmin));
+      vm.prank(proxyAdmin.owner());
+      proxyAdmin.upgrade(proxy, address(impl));
+    } else {
+      // sepolia has proxy admin as an eoa
+      vm.prank(proxyAdminAddress);
+      proxy.upgradeTo(address(impl));
+    }
+  }
+}