diff --git a/pywb/apps/frontendapp.py b/pywb/apps/frontendapp.py
index e03c632f..2de16fa6 100644
--- a/pywb/apps/frontendapp.py
+++ b/pywb/apps/frontendapp.py
@@ -494,6 +494,9 @@ class FrontEndApp(object):
             # store original script_name (original prefix) before modifications are made
             environ['pywb.app_prefix'] = environ.get('SCRIPT_NAME', '')
 
+            # store original script_name (original prefix) before modifications are made
+            environ['ORIG_SCRIPT_NAME'] = environ.get('SCRIPT_NAME')
+
             lang = args.pop('lang', '')
             if lang:
                 pop_path_info(environ)
diff --git a/pywb/apps/rewriterapp.py b/pywb/apps/rewriterapp.py
index 1186db75..335a77bf 100644
--- a/pywb/apps/rewriterapp.py
+++ b/pywb/apps/rewriterapp.py
@@ -267,6 +267,8 @@ class RewriterApp(object):
             'pywb.static_prefix', '/static/')
         is_proxy = ('wsgiprox.proxy_host' in environ)
 
+        environ['pywb.host_prefix'] = host_prefix
+
         if self.use_js_obj_proxy:
             content_rw = self.js_proxy_rw
         else:
diff --git a/pywb/templates/head_insert.html b/pywb/templates/head_insert.html
index b1fe7f59..e1506d83 100644
--- a/pywb/templates/head_insert.html
+++ b/pywb/templates/head_insert.html
@@ -3,7 +3,7 @@
 {% set urlsplit = cdx.url | urlsplit %}
   wbinfo = {};
   wbinfo.top_url = "{{ top_url }}";
-{% if is_framed %}
+{% if is_framed == 'true' %}
   // Fast Top-Frame Redirect
   if (window == window.top && wbinfo.top_url) {
     var loc = window.location.href.replace(window.location.hash, "");