diff --git a/dlls/oledb32/oledb_private.h b/dlls/oledb32/oledb_private.h
index 1c98fa063cdc7b48736777a487fbe26f5fff229b..a79d25146d1a41d249576dccded132cded9c8234 100644
--- a/dlls/oledb32/oledb_private.h
+++ b/dlls/oledb32/oledb_private.h
@@ -17,4 +17,4 @@
  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  */
 
-HRESULT create_oledb_convert(IUnknown *outer, void **obj);
+HRESULT create_oledb_convert(IUnknown *outer, void **obj) DECLSPEC_HIDDEN;