diff --git a/contracts/optimistic-ethereum/OVM/accounts/OVM_ProxyEOA.sol b/contracts/optimistic-ethereum/OVM/accounts/OVM_ProxyEOA.sol
index 0f376f821..904b23d2a 100644
--- a/contracts/optimistic-ethereum/OVM/accounts/OVM_ProxyEOA.sol
+++ b/contracts/optimistic-ethereum/OVM/accounts/OVM_ProxyEOA.sol
@@ -58,8 +58,8 @@ contract OVM_ProxyEOA {
                 return(add(returndata, 0x20), mload(returndata))
             }
         } else {
-            Lib_SafeExecutionManagerWrapper.safeREVERT(
-                string(returndata)
+            Lib_SafeExecutionManagerWrapper.safeREVERTbytes(
+                returndata
             );
         }
     }
diff --git a/contracts/optimistic-ethereum/OVM/execution/OVM_ExecutionManager.sol b/contracts/optimistic-ethereum/OVM/execution/OVM_ExecutionManager.sol
index 9c30f819b..266cb6bde 100644
--- a/contracts/optimistic-ethereum/OVM/execution/OVM_ExecutionManager.sol
+++ b/contracts/optimistic-ethereum/OVM/execution/OVM_ExecutionManager.sol
@@ -151,6 +151,8 @@ contract OVM_ExecutionManager is iOVM_ExecutionManager, Lib_AddressResolver {
      * Starts the execution of a transaction via the OVM_ExecutionManager.
      * @param _transaction Transaction data to be executed.
      * @param _ovmStateManager iOVM_StateManager implementation providing account state.
+     * @return `true` if the top-level CALL succeeded, `false` if it reverted.
+     * @return Data returned by the top-level CALL.
      */
     function run(
         Lib_OVMCodec.Transaction memory _transaction,
@@ -158,6 +160,10 @@ contract OVM_ExecutionManager is iOVM_ExecutionManager, Lib_AddressResolver {
     )
         override
         public
+        returns (
+            bool,
+            bytes memory
+        )
     {
         require(transactionContext.ovmNUMBER == 0, "Only be callable at the start of a transaction");
         // Store our OVM_StateManager instance (significantly easier than attempting to pass the
@@ -185,7 +191,7 @@ contract OVM_ExecutionManager is iOVM_ExecutionManager, Lib_AddressResolver {
         // reverts for INVALID_STATE_ACCESS.
         if (_isValidGasLimit(_transaction.gasLimit, _transaction.l1QueueOrigin) == false) {
             _resetContext();
-            return;
+            return (false, bytes(""));
         }
 
         // TEMPORARY: Gas metering is disabled for minnet.
@@ -193,7 +199,7 @@ contract OVM_ExecutionManager is iOVM_ExecutionManager, Lib_AddressResolver {
         // uint256 gasProvided = gasleft();
 
         // Run the transaction, make sure to meter the gas usage.
-        ovmCALL(
+        (bool success, bytes memory returndata) = ovmCALL(
             _transaction.gasLimit - gasMeterConfig.minTransactionGasLimit,
             _transaction.entrypoint,
             _transaction.data
@@ -209,6 +215,8 @@ contract OVM_ExecutionManager is iOVM_ExecutionManager, Lib_AddressResolver {
 
         // Reset the ovmStateManager.
         ovmStateManager = iOVM_StateManager(address(0));
+
+        return (success, returndata);
     }
 
 
diff --git a/contracts/optimistic-ethereum/OVM/predeploys/OVM_SequencerEntrypoint.sol b/contracts/optimistic-ethereum/OVM/predeploys/OVM_SequencerEntrypoint.sol
index bba7dd59c..4371719d4 100644
--- a/contracts/optimistic-ethereum/OVM/predeploys/OVM_SequencerEntrypoint.sol
+++ b/contracts/optimistic-ethereum/OVM/predeploys/OVM_SequencerEntrypoint.sol
@@ -89,13 +89,23 @@ contract OVM_SequencerEntrypoint {
             s
         );
 
-        Lib_SafeExecutionManagerWrapper.safeCALL(
+        (bool success, bytes memory returndata) = Lib_SafeExecutionManagerWrapper.safeCALL(
             gasleft(),
             target,
             callbytes
         );
+
+        if (success) {
+            assembly {
+                return(add(returndata, 0x20), mload(returndata))
+            }
+        } else {
+            Lib_SafeExecutionManagerWrapper.safeREVERTbytes(
+                returndata
+            );
+        }
     }
-    
+
 
     /**********************
      * Internal Functions *
diff --git a/contracts/optimistic-ethereum/iOVM/execution/iOVM_ExecutionManager.sol b/contracts/optimistic-ethereum/iOVM/execution/iOVM_ExecutionManager.sol
index 404822fc9..5e39c0776 100644
--- a/contracts/optimistic-ethereum/iOVM/execution/iOVM_ExecutionManager.sol
+++ b/contracts/optimistic-ethereum/iOVM/execution/iOVM_ExecutionManager.sol
@@ -75,7 +75,12 @@ interface iOVM_ExecutionManager {
     function run(
         Lib_OVMCodec.Transaction calldata _transaction,
         address _txStateManager
-    ) external;
+    )
+        external
+        returns (
+            bool,
+            bytes memory
+        );
 
 
     /*******************
diff --git a/contracts/optimistic-ethereum/libraries/wrappers/Lib_SafeExecutionManagerWrapper.sol b/contracts/optimistic-ethereum/libraries/wrappers/Lib_SafeExecutionManagerWrapper.sol
index 5ebe12fb4..c59c644b5 100644
--- a/contracts/optimistic-ethereum/libraries/wrappers/Lib_SafeExecutionManagerWrapper.sol
+++ b/contracts/optimistic-ethereum/libraries/wrappers/Lib_SafeExecutionManagerWrapper.sol
@@ -269,6 +269,23 @@ library Lib_SafeExecutionManagerWrapper {
         );
     }
 
+    /**
+     * Same as safeREVERT, but does *not* attach the sighash of Error(string).
+     * @param _revertdata Data to revert with.
+     */
+    function safeREVERTbytes(
+        bytes memory _revertdata
+    )
+        internal
+    {
+        _safeExecutionManagerInteraction(
+            abi.encodeWithSignature(
+                "ovmREVERT(bytes)",
+                _revertdata
+            )
+        );
+    }
+
     /**
      * Performs a safe "require".
      * @param _condition Boolean condition that must be true or will revert.
@@ -355,10 +372,6 @@ library Lib_SafeExecutionManagerWrapper {
             assembly {
                 revert(add(returndata, 0x20), mload(returndata))
             }
-        } else if (returndata.length == 1) {
-            assembly {
-                return(0, 1)
-            }
         } else {
             return returndata;
         }