diff --git a/reactos/win32ss/gdi/ntgdi/region.c b/reactos/win32ss/gdi/ntgdi/region.c
index 186bd437c0d..ee79eb23661 100644
--- a/reactos/win32ss/gdi/ntgdi/region.c
+++ b/reactos/win32ss/gdi/ntgdi/region.c
@@ -3506,6 +3506,7 @@ NtGdiCombineRgn(
     {
         DPRINT1("NtGdiCombineRgn invalid parameters: %p, %p, %p, %d\n",
                 hrgnDst, hrgnSrc1, hrgnSrc2, iMode);
+        EngSetLastError(ERROR_INVALID_HANDLE);
         return ERROR;
     }