1 files changed, 4 insertions, 0 deletions
diff --git a/lib/ast.js b/lib/ast.js
index 7b4c03d7..e8482d70 100644
--- a/lib/ast.js
+++ b/lib/ast.js
@@ -521,6 +521,10 @@ var AST_Lambda = DEFNODE("Lambda", "argnames length_read uses_arguments", {
     },
     each_argname: function(visit) {
         var tw = new TreeWalker(function(node) {
+            if (node instanceof AST_DefaultValue) {
+                node.name.walk(tw);
+                return true;
+            }
             if (node instanceof AST_DestructuredKeyVal) {
                 node.value.walk(tw);
                 return true;