diff --git a/pywb/static/wombat.js b/pywb/static/wombat.js
index c30f2105..52f204ed 100644
--- a/pywb/static/wombat.js
+++ b/pywb/static/wombat.js
@@ -321,6 +321,7 @@ _WBWombat = (function() {
         }
         this.assign = function(url) {
             var new_url = rewrite_url(url);
+            var orig = extract_orig(new_url);
             if (orig == this.href) {
                 return orig;
             }