diff --git a/src/xml/xml.cpp b/src/xml/xml.cpp
index 6cf9080002..21aa365003 100644
--- a/src/xml/xml.cpp
+++ b/src/xml/xml.cpp
@@ -143,7 +143,7 @@ bool wxXmlNode::HasProp(const wxString& propName) const
 
 bool wxXmlNode::GetPropVal(const wxString& propName, wxString *value) const
 {
-    wxCHECK_MSG( value, false, "value argument must not be NULL" );
+    wxCHECK_MSG( value, false, wxT("value argument must not be NULL") );
 
     wxXmlProperty *prop = GetProperties();