diff --git a/reactos/include/psdk/propidl.idl b/reactos/include/psdk/propidl.idl
index fbe80d8174e..488a53053f1 100644
--- a/reactos/include/psdk/propidl.idl
+++ b/reactos/include/psdk/propidl.idl
@@ -201,7 +201,7 @@ interface IPropertyStorage : IUnknown
     [case(VT_BYREF|VT_DISPATCH)]          IDispatch **ppdispVal;
     [case(VT_BYREF|VT_ARRAY)]             LPSAFEARRAY *pparray;
     [case(VT_BYREF|VT_VARIANT)]           PROPVARIANT *pvarVal;
-    };
+    } DUMMYUNIONNAME;
   };
 
   typedef struct tagPROPVARIANT *LPPROPVARIANT;