diff --git a/lib/6to5/types/index.js b/lib/6to5/types/index.js
index 75270807bf..a969003eaf 100644
--- a/lib/6to5/types/index.js
+++ b/lib/6to5/types/index.js
@@ -231,7 +231,7 @@ t.isReferenced = function (node, parent) {
     if (_.contains(parent.params, node)) return false;
 
     // we're a rest parameter
-    if (_.contains(parent.params, node)) return false;
+    if (parent.rest === node) return false;
   }
 
   if (t.isMethodDefinition(parent) && parent.key === node && !parent.computed) {