diff --git a/include/wx/xrc/xmlres.h b/include/wx/xrc/xmlres.h
index fe475b80b3..8699dd5d33 100644
--- a/include/wx/xrc/xmlres.h
+++ b/include/wx/xrc/xmlres.h
@@ -364,8 +364,7 @@ protected:
 
     // Returns true if the node has a property class equal to classname,
     // e.g. <object class="wxDialog">.
-    bool IsOfClass(wxXmlNode *node, const wxString& classname)
-        { return node->GetPropVal(wxT("class"), wxEmptyString) == classname; }
+    bool IsOfClass(wxXmlNode *node, const wxString& classname);
 
     // Gets node content from wxXML_ENTITY_NODE
     // The problem is, <tag>content<tag> is represented as
diff --git a/src/xrc/xmlres.cpp b/src/xrc/xmlres.cpp
index 789761a6e1..4d5f2d6b71 100644
--- a/src/xrc/xmlres.cpp
+++ b/src/xrc/xmlres.cpp
@@ -1147,6 +1147,14 @@ wxXmlNode *wxXmlResourceHandler::GetParamNode(const wxString& param)
 }
 
 
+
+bool wxXmlResourceHandler::IsOfClass(wxXmlNode *node, const wxString& classname)
+{
+    return node->GetPropVal(wxT("class"), wxEmptyString) == classname;
+}
+
+
+
 wxString wxXmlResourceHandler::GetNodeContent(wxXmlNode *node)
 {
     wxXmlNode *n = node;