diff --git a/reactos/dll/win32/msafd/misc/dllmain.c b/reactos/dll/win32/msafd/misc/dllmain.c
index 517d2209d17..7ce6976967a 100644
--- a/reactos/dll/win32/msafd/misc/dllmain.c
+++ b/reactos/dll/win32/msafd/misc/dllmain.c
@@ -1986,6 +1986,9 @@ WSPIoctl(IN  SOCKET Handle,
 				*lpcbBytesReturned = sizeof(ULONG);
 				return NO_ERROR;
 			}
+        case SIO_GET_EXTENSION_FUNCTION_POINTER:
+            *lpErrno = WSAEINVAL;
+            return SOCKET_ERROR;
         default:
 			*lpErrno = Socket->HelperData->WSHIoctl(Socket->HelperContext,
 													Handle,