diff --git a/lib/6to5/transformation/transformers/es6/tail-call.js b/lib/6to5/transformation/transformers/es6/tail-call.js
index 0704275fee..2cc9ec4fed 100644
--- a/lib/6to5/transformation/transformers/es6/tail-call.js
+++ b/lib/6to5/transformation/transformers/es6/tail-call.js
@@ -65,7 +65,7 @@ TailCallTransformer.prototype.hasDeopt = function () {
   // check if the ownerId has been reassigned, if it has then it's not safe to
   // perform optimisations
   var ownerIdInfo = this.scope.getBindingInfo(this.ownerId.name);
-  return ownerIdInfo && !ownerIdInfo.reassigned;
+  return ownerIdInfo && ownerIdInfo.reassigned;
 };
 
 TailCallTransformer.prototype.run = function () {