diff -r fee8732830f7 -r e8d86272e6ea app/soc/views/helper/requests.py
--- a/app/soc/views/helper/requests.py	Mon Sep 07 20:02:35 2009 +0200
+++ b/app/soc/views/helper/requests.py	Mon Sep 07 20:06:27 2009 +0200
@@ -22,9 +22,10 @@
   ]
 
 
-import os
 import urlparse
 
+from soc.logic import system
+
 
 def getSingleIndexedParamValue(request, param_name, values=()):
   """Returns a value indexed by a query parameter in the HTTP request.
@@ -119,7 +120,7 @@
     # no HTTP referrer, so cannot possibly start with expected prefix
     return False
 
-  http_host = 'http://%s/%s' % (os.environ['HTTP_HOST'], url_name)
+  http_host = 'http://%s/%s' % (system.getHostname(), url_name)
 
   if http_from.startswith(http_host):
     return True