diff --git a/include/wx/ustring.h b/include/wx/ustring.h
index 25934f6dc4..7790ac1656 100644
--- a/include/wx/ustring.h
+++ b/include/wx/ustring.h
@@ -134,9 +134,9 @@ public:
        return utf16_str();
     }
 #else
-    wchar_t *wc_str() const
+    const wchar_t *wc_str() const
     {
-        return (wchar_t*) c_str();
+        return c_str();
     }
 #endif
 
@@ -154,18 +154,18 @@ public:
     }
 
 #if wxUSE_UNICODE_UTF8
-    wxScopedCharBuffer wx_str()
+    wxScopedCharBuffer wx_str() const
     {
         return utf8_str();
     }
 #else
 #if SIZEOF_WCHAR_T == 2
-    wxScopedWCharBuffer wx_str()
+    wxScopedWCharBuffer wx_str() const
     {
         return utf16_str();
     }
 #else
-    const wchar_t* wx_str()
+    const wchar_t* wx_str() const
     {
         return c_str();
     }