diff --git a/web3/engine_api_types.nim b/web3/engine_api_types.nim
index ed1c2ed..8b824d2 100644
--- a/web3/engine_api_types.nim
+++ b/web3/engine_api_types.nim
@@ -35,15 +35,10 @@ type
     syncing = "SYNCING"
 
   ForkchoiceUpdatedResponse* = object
-    status*: ForkchoiceUpdatedStatus
+    status*: string
     payloadId*: Option[Quantity]
 
 const
-  # https://github.com/ethereum/execution-apis/blob/v1.0.0-alpha.4/src/engine/specification.md#errors
-  PARSE_ERROR* = -32700
-  INVALID_REQUEST* = -32600
-  METHOD_NOT_FOUND* = -32601
-  INVALID_PARAMS* = -32602
-  INTERNAL_ERROR* = -32603
-  SERVER_ERROR* = -32000
-  UNKNOWN_PAYLOAD* = -32001
+  # https://github.com/ethereum/execution-apis/blob/v1.0.0-alpha.4/src/engine/interop/specification.md#error-codes
+  UNKNOWN_HEADER* = 4
+  UNKNOWN_PAYLOAD* = 5