diff --git a/reactos/include/psdk/shlobj.h b/reactos/include/psdk/shlobj.h
index f58d66e4c7b..a496959b0a4 100644
--- a/reactos/include/psdk/shlobj.h
+++ b/reactos/include/psdk/shlobj.h
@@ -1530,7 +1530,7 @@ typedef struct tagOPENASINFO {
 	OPEN_AS_INFO_FLAGS oaifInFlags;
 } OPENASINFO;
 
-HRESULT SHOpenWithDialog(
+HRESULT WINAPI SHOpenWithDialog(
   HWND hwndParent,
   const OPENASINFO *poainfo
 );