1 files changed, 3 insertions, 1 deletions
diff --git a/lib/scope.js b/lib/scope.js
index 0f94d4e8..f638890f 100644
--- a/lib/scope.js
+++ b/lib/scope.js
@@ -433,7 +433,9 @@ AST_Symbol.DEFMETHOD("mark_enclosed", function(options) {
     var def = this.definition();
     for (var s = this.scope; s; s = s.parent_scope) {
         push_uniq(s.enclosed, def);
-        if (options.keep_fnames) {
+        if (!options) {
+            delete s._var_names;
+        } else if (options.keep_fnames) {
             s.functions.each(function(d) {
                 push_uniq(def.scope.enclosed, d);
             });