diff --git a/reactos/win32ss/user/ntuser/guicheck.h b/reactos/win32ss/user/ntuser/guicheck.h
index 77d955f7e2c..37923437d6f 100644
--- a/reactos/win32ss/user/ntuser/guicheck.h
+++ b/reactos/win32ss/user/ntuser/guicheck.h
@@ -1,7 +1,7 @@
 #pragma once
 
 BOOL FASTCALL co_IntGraphicsCheck(BOOL Create);
-VOID FASTCALL co_IntUserManualGuiCheck(LONG Check);
+VOID FASTCALL co_IntUserManualGuiCheck(BOOL Create);
 BOOL FASTCALL IntCreatePrimarySurface(VOID);
 VOID FASTCALL IntDestroyPrimarySurface(VOID);