diff --git a/lib/traverse.js b/lib/traverse.js
index d8eae1d..b10e657 100644
--- a/lib/traverse.js
+++ b/lib/traverse.js
@@ -11,6 +11,9 @@ function Traverse (refObj) {
             Object.keys(ref).forEach(function (key) {
                 node[key] = clone(ref[key]);
             });
+            // To make instanceof work:
+            if ('__proto__' in ref) node.__proto__ = ref.__proto__;
+            // Probably there are other attributes worth copying
             return node;
         }
         else {