diff --git a/include/objbase.h b/include/objbase.h
index 75280d6de70..0eae397b43a 100644
--- a/include/objbase.h
+++ b/include/objbase.h
@@ -392,6 +392,7 @@ HRESULT WINAPI CoRegisterChannelHook(REFGUID ExtensionGuid, IChannelHook *pChann
 
 typedef enum tagCOWAIT_FLAGS
 {
+    COWAIT_DEFAULT        = 0x00000000,
     COWAIT_WAITALL        = 0x00000001,
     COWAIT_ALERTABLE      = 0x00000002,
     COWAIT_INPUTAVAILABLE = 0x00000004