diff --git a/solidity/contracts/bridges/OptimismReceiverAdapter.sol b/solidity/contracts/bridges/OptimismReceiverAdapter.sol
index 577505e..e2035bb 100644
--- a/solidity/contracts/bridges/OptimismReceiverAdapter.sol
+++ b/solidity/contracts/bridges/OptimismReceiverAdapter.sol
@@ -7,12 +7,17 @@ import {ICrossDomainMessenger} from '../../interfaces/bridges/ICrossDomainMessen
 import {IOracleSidechain} from '../../interfaces/IOracleSidechain.sol';
 
 contract OptimismReceiverAdapter is BridgeReceiverAdapter {
+  ICrossDomainMessenger public immutable messenger;
+  address public immutable source;
+
   constructor(
     IDataReceiver _dataReceiver,
-    address _source,
-    uint32 _originDomain
+    address _messenger,
+    address _source
   ) BridgeReceiverAdapter(_dataReceiver) {
-    if (false) revert ZeroAddress();
+    if (_messenger == address(0) || _source == address(0)) revert ZeroAddress();
+    messenger = ICrossDomainMessenger(_messenger);
+    source = _source;
   }
 
   function addObservations(
@@ -24,7 +29,7 @@ contract OptimismReceiverAdapter is BridgeReceiverAdapter {
   }
 
   modifier onlyExecutor() {
-    // if (msg.sender != address(connext) || _originSender != source || _originDomain != originDomain) revert UnauthorizedCaller();
+    if (msg.sender != address(messenger) || messenger.xDomainMessageSender() != source) revert UnauthorizedCaller();
     _;
   }
 }
diff --git a/solidity/interfaces/bridges/IBridgeReceiverAdapter.sol b/solidity/interfaces/bridges/IBridgeReceiverAdapter.sol
index d1c4f5a..9823a92 100644
--- a/solidity/interfaces/bridges/IBridgeReceiverAdapter.sol
+++ b/solidity/interfaces/bridges/IBridgeReceiverAdapter.sol
@@ -13,4 +13,9 @@ interface IBridgeReceiverAdapter is IBaseErrors {
   function dataReceiver() external view returns (IDataReceiver _dataReceiver);
 
   /* NOTE: callback methods should be here declared */
+
+  // ERRORS
+
+  /// @notice Thrown if a caller is not authorized
+  error UnauthorizedCaller();
 }
diff --git a/solidity/interfaces/bridges/IConnextReceiverAdapter.sol b/solidity/interfaces/bridges/IConnextReceiverAdapter.sol
index 0717f33..7a40fd1 100644
--- a/solidity/interfaces/bridges/IConnextReceiverAdapter.sol
+++ b/solidity/interfaces/bridges/IConnextReceiverAdapter.sol
@@ -12,16 +12,11 @@ interface IConnextReceiverAdapter is IXReceiver, IBridgeReceiverAdapter {
   /// @return _connext Address of the ConnextHandler contract
   function connext() external view returns (IConnext _connext);
 
-  /// @notice Gets the DAO that is expected as the xcaller
+  /// @notice Gets the contract address that is expected as the xcaller
   /// @return _originContract Address of the xcaller contract
   function source() external view returns (address _originContract);
 
   /// @notice Gets the origin domain id
   /// @return _originDomain The origin domain id
   function originDomain() external view returns (uint32 _originDomain);
-
-  // ERRORS
-
-  /// @notice Thrown if a caller is not authorized
-  error UnauthorizedCaller();
 }