diff --git a/include/wx/convauto.h b/include/wx/convauto.h
index caab99973f..23b21dc41c 100644
--- a/include/wx/convauto.h
+++ b/include/wx/convauto.h
@@ -78,6 +78,8 @@ public:
 
     virtual size_t GetMBNulLen() const wxOVERRIDE { return m_conv->GetMBNulLen(); }
 
+    virtual bool IsUTF8() const wxOVERRIDE { return m_conv && m_conv->IsUTF8(); }
+
     virtual wxMBConv *Clone() const wxOVERRIDE { return new wxConvAuto(*this); }
 
     // return the BOM type of this buffer