diff --git a/reactos/include/psdk/msxml2.idl b/reactos/include/psdk/msxml2.idl
index b834b091cb0..84555784f61 100644
--- a/reactos/include/psdk/msxml2.idl
+++ b/reactos/include/psdk/msxml2.idl
@@ -1286,7 +1286,7 @@ interface IXSLProcessor : IDispatch
     HRESULT addParameter(
         [in] BSTR p, 
         [in] VARIANT var, 
-        [in, defaultvalue("")] BSTR uri);
+        [in, defaultvalue(L"")] BSTR uri);
 
     [id(DISPID_XMLDOM_PROCESSOR_ADDOBJECT)]
     HRESULT addObject(