diff --git a/include/winuser.h b/include/winuser.h
index a46355b6922..b2877d4fe25 100644
--- a/include/winuser.h
+++ b/include/winuser.h
@@ -4441,7 +4441,7 @@ BOOL      WINAPI UnionRect(LPRECT,const RECT*,const RECT*);
 BOOL      WINAPI UnregisterClassA(LPCSTR,HINSTANCE);
 BOOL      WINAPI UnregisterClassW(LPCWSTR,HINSTANCE);
 #define     UnregisterClass WINELIB_NAME_AW(UnregisterClass)
-VOID        WINAPI UpdateWindow(HWND);
+BOOL        WINAPI UpdateWindow(HWND);
 UINT        WINAPI UserRealizePalette(HDC);
 BOOL        WINAPI ValidateRect(HWND,const RECT*);
 BOOL        WINAPI ValidateRgn(HWND,HRGN);
diff --git a/windows/painting.c b/windows/painting.c
index 079c4a8d085..aa3600b8f92 100644
--- a/windows/painting.c
+++ b/windows/painting.c
@@ -852,9 +852,9 @@ END:
 /***********************************************************************
  *		UpdateWindow (USER32.@)
  */
-void WINAPI UpdateWindow( HWND hwnd )
+BOOL WINAPI UpdateWindow( HWND hwnd )
 {
-    RedrawWindow( hwnd, NULL, 0, RDW_UPDATENOW | RDW_ALLCHILDREN );
+    return RedrawWindow( hwnd, NULL, 0, RDW_UPDATENOW | RDW_ALLCHILDREN );
 }