diff --git a/pallets/rolldown/src/lib.rs b/pallets/rolldown/src/lib.rs
index 24eb15d067..7d17c8e2c1 100644
--- a/pallets/rolldown/src/lib.rs
+++ b/pallets/rolldown/src/lib.rs
@@ -6,7 +6,7 @@ use frame_support::{
 	StorageHasher,
 };
 use frame_system::{ensure_signed, pallet_prelude::*};
-use messages::UpdateType;
+use messages::{PendingRequestType, UpdateType};
 use sp_runtime::traits::SaturatedConversion;
 
 use alloy_sol_types::SolValue;
@@ -158,6 +158,8 @@ pub mod pallet {
 		EmptyUpdate,
 		AddressDeserializationFailure,
 		RequestDoesNotExist,
+		TooManyRequests,
+		InvalidUpdate,
 	}
 
 	#[pallet::config]
@@ -215,6 +217,39 @@ pub mod pallet {
 			let sequencer = ensure_signed(origin)?;
 
 			ensure!(!requests.order.is_empty(), Error::<T>::EmptyUpdate);
+			ensure!(requests.order.len() <= 10, Error::<T>::TooManyRequests);
+
+			let withdraws_count = requests.pendingWithdraws.len();
+			let deposits_count = requests.pendingDeposits.len();
+			let cancels_count = requests.pendingCancelResultions.len();
+			let l2_updates_count = requests.pendingL2UpdatesToRemove.len();
+
+			ensure!(
+				requests.order.iter().filter(|e| **e == PendingRequestType::DEPOSIT).count() ==
+					deposits_count,
+				Error::<T>::InvalidUpdate
+			);
+			ensure!(
+				requests.order.iter().filter(|e| **e == PendingRequestType::WITHDRAWAL).count() ==
+					withdraws_count,
+				Error::<T>::InvalidUpdate
+			);
+			ensure!(
+				requests
+					.order
+					.iter()
+					.filter(|e| **e == PendingRequestType::CANCEL_RESOLUTION)
+					.count() == cancels_count,
+				Error::<T>::InvalidUpdate
+			);
+			ensure!(
+				requests
+					.order
+					.iter()
+					.filter(|e| **e == PendingRequestType::L2_UPDATES_TO_REMOVE)
+					.count() == l2_updates_count,
+				Error::<T>::InvalidUpdate
+			);
 
 			// check json length to prevent big data spam, maybe not necessary as it will be checked later and slashed
 			let current_block_number =
diff --git a/pallets/rolldown/src/messages.rs b/pallets/rolldown/src/messages.rs
index 8301d20dc6..de7f323f78 100644
--- a/pallets/rolldown/src/messages.rs
+++ b/pallets/rolldown/src/messages.rs
@@ -52,6 +52,7 @@ pub struct L1Update {
 	pub pendingL2UpdatesToRemove: Vec<L2UpdatesToRemove>,
 }
 
+#[derive(Eq, PartialEq, RuntimeDebug, Clone, Encode, Decode, TypeInfo, Serialize)]
 pub enum L1UpdateRequest {
 	Withdraw(Withdraw),
 	Deposit(Deposit),
diff --git a/pallets/rolldown/src/tests.rs b/pallets/rolldown/src/tests.rs
index 5579152d9e..c7958d7c83 100644
--- a/pallets/rolldown/src/tests.rs
+++ b/pallets/rolldown/src/tests.rs
@@ -176,6 +176,35 @@ fn deposit_executed_after_dispute_period() {
 		});
 }
 
+#[test]
+#[serial]
+fn each_request_executed_only_once() {
+	ExtBuilder::new()
+		.issue(ALICE, ETH_TOKEN_ADDRESS_MGX, 0u128)
+		.execute_with_default_mocks(|| {
+			forward_to_block::<Test>(10);
+			let update = create_l1_update(vec![L1UpdateRequest::Deposit(messages::Deposit {
+				depositRecipient: DummyAddressConverter::convert_back(CHARLIE),
+				tokenAddress: ETH_TOKEN_ADDRESS,
+				amount: sp_core::U256::from(MILLION),
+			})]);
+			Rolldown::update_l2_from_l1(RuntimeOrigin::signed(ALICE), update.clone()).unwrap();
+
+			forward_to_block::<Test>(11);
+			Rolldown::update_l2_from_l1(RuntimeOrigin::signed(BOB), update).unwrap();
+
+			forward_to_block::<Test>(14);
+			assert!(!pending_updates::<Test>::contains_key(sp_core::U256::from(0u128)));
+			assert_eq!(TokensOf::<Test>::free_balance(ETH_TOKEN_ADDRESS_MGX, &CHARLIE), 0_u128);
+
+			forward_to_block::<Test>(15);
+			assert_eq!(TokensOf::<Test>::free_balance(ETH_TOKEN_ADDRESS_MGX, &CHARLIE), MILLION);
+
+			forward_to_block::<Test>(20);
+			assert_eq!(TokensOf::<Test>::free_balance(ETH_TOKEN_ADDRESS_MGX, &CHARLIE), MILLION);
+		});
+}
+
 #[test]
 #[serial]
 fn withdraw_executed_after_dispute_period() {
@@ -336,6 +365,46 @@ fn cancel_request() {
 		});
 }
 
+#[test]
+#[serial]
+fn reject_update_with_too_many_requests() {
+	ExtBuilder::new().execute_with_default_mocks(|| {
+		forward_to_block::<Test>(10);
+
+		let requests = vec![
+			L1UpdateRequest::Withdraw(messages::Withdraw {
+				depositRecipient: ETH_RECIPIENT_ACCOUNT,
+				tokenAddress: ETH_TOKEN_ADDRESS,
+				amount: sp_core::U256::from(MILLION),
+			});
+			11
+		];
+
+		let withdraw_update = create_l1_update(requests);
+
+		assert_err!(
+			Rolldown::update_l2_from_l1(RuntimeOrigin::signed(ALICE), withdraw_update),
+			Error::<Test>::TooManyRequests
+		);
+	});
+}
+
+#[test]
+#[serial]
+fn reject_update_with_missing_requests() {
+	ExtBuilder::new().execute_with_default_mocks(|| {
+		forward_to_block::<Test>(10);
+
+		let update =
+			L1Update { order: vec![messages::PendingRequestType::DEPOSIT], ..Default::default() };
+
+		assert_err!(
+			Rolldown::update_l2_from_l1(RuntimeOrigin::signed(ALICE), update),
+			Error::<Test>::InvalidUpdate
+		);
+	});
+}
+
 #[test]
 fn test_conversion_u256() {
 	let val = sp_core::U256::from(1u8);