diff --git a/contracts/protocol/switchboard/EVMxSwitchboard.sol b/contracts/protocol/switchboard/EVMxSwitchboard.sol
index 0fd6b253..d422f12b 100644
--- a/contracts/protocol/switchboard/EVMxSwitchboard.sol
+++ b/contracts/protocol/switchboard/EVMxSwitchboard.sol
@@ -266,7 +266,13 @@ contract EVMxSwitchboard is SwitchboardBase {
 
         address watcher = _recoverSigner(
             keccak256(
-                abi.encodePacked(toBytes32Format(address(this)), chainSlug, oldDigest, newDigest)
+                abi.encodePacked(
+                    toBytes32Format(address(this)),
+                    chainSlug,
+                    oldDigest,
+                    newDigest,
+                    nonce_
+                )
             ),
             signature_
         );
diff --git a/contracts/protocol/switchboard/MessageSwitchboard.sol b/contracts/protocol/switchboard/MessageSwitchboard.sol
index ee15ea3d..dbacb999 100644
--- a/contracts/protocol/switchboard/MessageSwitchboard.sol
+++ b/contracts/protocol/switchboard/MessageSwitchboard.sol
@@ -697,7 +697,13 @@ contract MessageSwitchboard is SwitchboardBase, ReentrancyGuard {
 
         address watcher = _recoverSigner(
             keccak256(
-                abi.encodePacked(toBytes32Format(address(this)), chainSlug, oldDigest, newDigest)
+                abi.encodePacked(
+                    toBytes32Format(address(this)),
+                    chainSlug,
+                    oldDigest,
+                    newDigest,
+                    nonce_
+                )
             ),
             signature_
         );
diff --git a/test/protocol/switchboard/EVMxSwitchboard.t.sol b/test/protocol/switchboard/EVMxSwitchboard.t.sol
index 5b616e38..ae117217 100644
--- a/test/protocol/switchboard/EVMxSwitchboard.t.sol
+++ b/test/protocol/switchboard/EVMxSwitchboard.t.sol
@@ -284,18 +284,25 @@ contract EVMxSwitchboardTestBase is Test, Utils {
      */
     function _createAssignTransmitterSignature(
         DigestParams memory digestParams_,
-        address newTransmitter_
+        address newTransmitter_,
+        uint256 nonce_
     ) internal view returns (bytes memory signature) {
         // Create old digest with current transmitter (before modification)
         bytes32 oldDigest = createDigest(digestParams_);
-        
+
         // Create new digest with new transmitter
         digestParams_.transmitter = toBytes32Format(newTransmitter_);
         bytes32 newDigest = createDigest(digestParams_);
 
         // Create signature digest with both old and new digests
         bytes32 signatureDigest = keccak256(
-            abi.encodePacked(toBytes32Format(address(evmxSwitchboard)), CHAIN_SLUG, oldDigest, newDigest)
+            abi.encodePacked(
+                toBytes32Format(address(evmxSwitchboard)),
+                CHAIN_SLUG,
+                oldDigest,
+                newDigest,
+                nonce_
+            )
         );
         signature = createSignature(signatureDigest, watcherPrivateKey);
     }
@@ -1179,7 +1186,11 @@ contract SocketPayloadIdVerificationTest is EVMxSwitchboardTestBase {
         assertEq(oldDigest, storedDigest, "Old digest should match stored digest");
 
         // Create signature for new transmitter
-        bytes memory signature = _createAssignTransmitterSignature(digestParams, newTransmitter);
+        bytes memory signature = _createAssignTransmitterSignature(
+            digestParams,
+            newTransmitter,
+            nonce
+        );
 
         // Create new digest for verification
         digestParams.transmitter = toBytes32Format(newTransmitter);
@@ -1229,7 +1240,11 @@ contract SocketPayloadIdVerificationTest is EVMxSwitchboardTestBase {
         );
 
         // Create signature for new transmitter
-        bytes memory signature = _createAssignTransmitterSignature(digestParams, newTransmitter);
+        bytes memory signature = _createAssignTransmitterSignature(
+            digestParams,
+            newTransmitter,
+            nonce
+        );
 
         // Should revert because old digest doesn't match stored digest
         vm.prank(getWatcherAddress());
@@ -1271,14 +1286,19 @@ contract SocketPayloadIdVerificationTest is EVMxSwitchboardTestBase {
 
         // Create old digest with old transmitter
         bytes32 oldDigest = createDigest(digestParams);
-        
+
         // Create new digest with new transmitter
         digestParams.transmitter = toBytes32Format(newTransmitter);
         bytes32 newDigest = createDigest(digestParams);
 
         // Create signature digest with both old and new digests with non-watcher key
         bytes32 signatureDigest = keccak256(
-            abi.encodePacked(toBytes32Format(address(evmxSwitchboard)), CHAIN_SLUG, oldDigest, newDigest)
+            abi.encodePacked(
+                toBytes32Format(address(evmxSwitchboard)),
+                CHAIN_SLUG,
+                oldDigest,
+                newDigest
+            )
         );
         bytes memory signature = createSignature(signatureDigest, nonWatcherKey);
 
@@ -1320,7 +1340,11 @@ contract SocketPayloadIdVerificationTest is EVMxSwitchboardTestBase {
         );
 
         // Create signature for new transmitter
-        bytes memory signature = _createAssignTransmitterSignature(digestParams, newTransmitter);
+        bytes memory signature = _createAssignTransmitterSignature(
+            digestParams,
+            newTransmitter,
+            nonce
+        );
 
         // First call succeeds
         vm.prank(getWatcherAddress());
@@ -1349,7 +1373,8 @@ contract SocketPayloadIdVerificationTest is EVMxSwitchboardTestBase {
         // Create signature for the new assignment
         bytes memory signature2 = _createAssignTransmitterSignature(
             updatedDigestParams,
-            anotherNewTransmitter
+            anotherNewTransmitter,
+            nonce
         );
 
         vm.prank(getWatcherAddress());
diff --git a/test/protocol/switchboard/MessageSwitchboard.t.sol b/test/protocol/switchboard/MessageSwitchboard.t.sol
index 7437580d..d90aa293 100644
--- a/test/protocol/switchboard/MessageSwitchboard.t.sol
+++ b/test/protocol/switchboard/MessageSwitchboard.t.sol
@@ -517,7 +517,8 @@ contract MessageSwitchboardTest is Test, Utils {
      */
     function _createAssignTransmitterSignature(
         DigestParams memory digestParams_,
-        address newTransmitter_
+        address newTransmitter_,
+        uint256 nonce_
     ) internal view returns (bytes memory signature) {
         // Create old digest with current transmitter (before modification)
         bytes32 oldDigest = createDigest(digestParams_);
@@ -532,7 +533,8 @@ contract MessageSwitchboardTest is Test, Utils {
                 toBytes32Format(address(messageSwitchboard)),
                 SRC_CHAIN,
                 oldDigest,
-                newDigest
+                newDigest,
+                nonce_
             )
         );
         signature = createSignature(signatureDigest, watcherPrivateKey);
@@ -2446,7 +2448,11 @@ contract MessageSwitchboardTest is Test, Utils {
         assertEq(oldDigest, storedDigest, "Old digest should match stored digest");
 
         // Create signature for new transmitter
-        bytes memory signature = _createAssignTransmitterSignature(digestParams, newTransmitter);
+        bytes memory signature = _createAssignTransmitterSignature(
+            digestParams,
+            newTransmitter,
+            nonce
+        );
 
         // Create new digest for verification
         digestParams.transmitter = toBytes32Format(newTransmitter);
@@ -2496,7 +2502,11 @@ contract MessageSwitchboardTest is Test, Utils {
         );
 
         // Create signature for new transmitter
-        bytes memory signature = _createAssignTransmitterSignature(digestParams, newTransmitter);
+        bytes memory signature = _createAssignTransmitterSignature(
+            digestParams,
+            newTransmitter,
+            nonce
+        );
 
         // Should revert because old digest doesn't match stored digest
         vm.prank(getWatcherAddress());
@@ -2592,7 +2602,11 @@ contract MessageSwitchboardTest is Test, Utils {
         );
 
         // Create signature for new transmitter
-        bytes memory signature = _createAssignTransmitterSignature(digestParams, newTransmitter);
+        bytes memory signature = _createAssignTransmitterSignature(
+            digestParams,
+            newTransmitter,
+            nonce
+        );
 
         // First call succeeds
         vm.prank(getWatcherAddress());
@@ -2621,7 +2635,8 @@ contract MessageSwitchboardTest is Test, Utils {
         // Create signature for the new assignment
         bytes memory signature2 = _createAssignTransmitterSignature(
             updatedDigestParams,
-            anotherNewTransmitter
+            anotherNewTransmitter,
+            nonce
         );
 
         vm.prank(getWatcherAddress());