diff --git a/include/wx/motif/private.h b/include/wx/motif/private.h
index 9895862d9d..5b05c6e249 100644
--- a/include/wx/motif/private.h
+++ b/include/wx/motif/private.h
@@ -141,7 +141,11 @@ class wxXmString
 {
     void Init(const char *str)
     {
-        m_string = XmStringCreateLtoR((char *)str, XmSTRING_DEFAULT_CHARSET);
+        m_string = XmStringCreateLtoR
+                   (
+                    const_cast<char *>(str),
+                    const_cast<char *>(XmSTRING_DEFAULT_CHARSET)
+                   );
     }
 
 public: