diff --git a/src/lib/base.html b/src/lib/base.html
index 8cf9a3b444..1223d4e438 100644
--- a/src/lib/base.html
+++ b/src/lib/base.html
@@ -40,7 +40,9 @@
     },
 
     createdCallback: function() {
-      this._ensureRegisterFinished(this.__proto__);
+      if (!this.__hasRegisterFinished) {
+        this._ensureRegisterFinished(this.__proto__);
+      }
       Polymer.telemetry.instanceCount++;
       this.root = this;
       this._doBehavior('created'); // abstract