diff --git a/lib/hash.js b/lib/hash.js
index a55c478..613dfc5 100644
--- a/lib/hash.js
+++ b/lib/hash.js
@@ -42,7 +42,7 @@ function Hash (hash, extra) {
             return self;
         },
         merge : function (h) {
-            return self.clone.update(h);
+            return self.copy.update(h);
         },
         tap : function (f) {
             f.call(self, hash);