diff --git a/‎src/lib/template/templatizer.html‎
Lines changed: 3 additions & 0 deletions b/‎src/lib/template/templatizer.html‎
Lines changed: 3 additions & 0 deletions
@@ -298,6 +298,9 @@
     // values (_propertySetter back on instance once accessor is installed)
     _extendTemplate: function(template, proto) {
       var n$ = Object.getOwnPropertyNames(proto);
+      if (proto._propertySetter) {
+        template._propertySetter = proto._propertySetter;
+      }
       for (var i=0, n; (i<n$.length) && (n=n$[i]); i++) {
         var val = template[n];
         var pd = Object.getOwnPropertyDescriptor(proto, n);