diff --git a/rtl/win/wininc/redef.inc b/rtl/win/wininc/redef.inc
index eae7dae581..01f69e3aef 100644
--- a/rtl/win/wininc/redef.inc
+++ b/rtl/win/wininc/redef.inc
@@ -30,6 +30,7 @@ type
   TFNThreadStartRoutine = FARPROC;
   TFNTimerAPCRoutine    = FARPROC;
   TFNFiberStartRoutine  = FARPROC;
+  TFNHookProc =  HOOKPROC;
 
   PObjectTypeList = ^TObjectTypeList;
   _OBJECT_TYPE_LIST = record