diff --git a/programs/protocol-contracts-solana/src/lib.rs b/programs/protocol-contracts-solana/src/lib.rs
index 78e5677..0c897b5 100644
--- a/programs/protocol-contracts-solana/src/lib.rs
+++ b/programs/protocol-contracts-solana/src/lib.rs
@@ -33,11 +33,12 @@ declare_id!("94U5AHQMKkV5txNJ17QPXWoh474PheGou6cNP2FEuL1d");
 pub mod gateway {
     use super::*;
 
-    pub fn initialize(ctx: Context<Initialize>, tss_address:[u8; 20]) -> Result<()> {
+    pub fn initialize(ctx: Context<Initialize>, tss_address:[u8; 20], chain_id: u64) -> Result<()> {
         let initialized_pda = &mut ctx.accounts.pda;
         initialized_pda.nonce = 0;
         initialized_pda.tss_address = tss_address;
         initialized_pda.authority = ctx.accounts.signer.key();
+        initialized_pda.chain_id = chain_id;
 
         Ok(())
     }
@@ -108,6 +109,7 @@ pub mod gateway {
             return err!(Errors::NonceMismatch);
         }
         let mut concatenated_buffer = Vec::new();
+        concatenated_buffer.extend_from_slice(&pda.chain_id.to_be_bytes());
         concatenated_buffer.extend_from_slice(&nonce.to_be_bytes());
         concatenated_buffer.extend_from_slice(&amount.to_be_bytes());
         concatenated_buffer.extend_from_slice(&ctx.accounts.to.key().to_bytes());
@@ -144,6 +146,7 @@ pub mod gateway {
             return err!(Errors::NonceMismatch);
         }
         let mut concatenated_buffer = Vec::new();
+        concatenated_buffer.extend_from_slice(&pda.chain_id.to_be_bytes());
         concatenated_buffer.extend_from_slice(&nonce.to_be_bytes());
         concatenated_buffer.extend_from_slice(&amount.to_be_bytes());
         concatenated_buffer.extend_from_slice(&ctx.accounts.to.key().to_bytes());
@@ -272,6 +275,7 @@ pub struct Pda {
     nonce: u64,            // ensure that each signature can only be used once
     tss_address: [u8; 20], // 20 bytes address format of ethereum
     authority: Pubkey,
+    chain_id: u64,
 }
 
 
diff --git a/tests/protocol-contracts-solana.ts b/tests/protocol-contracts-solana.ts
index e28c469..9e3dfde 100644
--- a/tests/protocol-contracts-solana.ts
+++ b/tests/protocol-contracts-solana.ts
@@ -49,12 +49,15 @@ describe("some tests", () => {
     const tssAddress = Array.from(address);
     console.log("tss address", tssAddress);
 
+    const chain_id = 111111;
+    const chain_id_bn = new anchor.BN(chain_id);
+
     it("Initializes the program", async () => {
-        await gatewayProgram.methods.initialize(tssAddress).rpc();
+        await gatewayProgram.methods.initialize(tssAddress, chain_id_bn).rpc();
 
         // repeated initialization should fail
         try {
-            await gatewayProgram.methods.initialize(tssAddress).rpc();
+            await gatewayProgram.methods.initialize(tssAddress,chain_id_bn).rpc();
             throw new Error("Expected error not thrown"); // This line will make the test fail if no error is thrown
         } catch (err) {
             expect(err).to.be.not.null;
@@ -181,6 +184,7 @@ describe("some tests", () => {
         const amount = new anchor.BN(500_000);
         const nonce = pdaAccountData.nonce;
         const buffer = Buffer.concat([
+            chain_id_bn.toArrayLike(Buffer, 'be', 8),
             nonce.toArrayLike(Buffer, 'be', 8),
             amount.toArrayLike(Buffer, 'be', 8),
             wallet_ata.toBuffer(),
@@ -247,6 +251,7 @@ describe("some tests", () => {
         const amount = new anchor.BN(500000000);
         const to = wallet.publicKey;
         const buffer = Buffer.concat([
+            chain_id_bn.toArrayLike(Buffer, 'be', 8),
             nonce.toArrayLike(Buffer, 'be', 8),
             amount.toArrayLike(Buffer, 'be', 8),
             to.toBuffer(),
@@ -294,6 +299,8 @@ describe("some tests", () => {
             expect(err.message).to.include("SignerIsNotAuthority");
         }
     });
+
+
 });