diff --git a/lib/6to5/transformation/transformers/es6/parameters.default.js b/lib/6to5/transformation/transformers/es6/parameters.default.js
index 942e3139cf..18c113c46b 100644
--- a/lib/6to5/transformation/transformers/es6/parameters.default.js
+++ b/lib/6to5/transformation/transformers/es6/parameters.default.js
@@ -55,7 +55,7 @@ exports.Function = function (node, parent, scope, file) {
     var param = node.params[i];
 
     if (!t.isAssignmentPattern(param)) {
-      if (!t.isBindingElement(param)) {
+      if (!t.isRestElement(param)) {
         lastNonDefaultParam = i + 1;
       }