diff --git a/war/WEB-INF/appengine-web.xml b/war/WEB-INF/appengine-web.xml
index adf7c32..7a8aede 100644
--- a/war/WEB-INF/appengine-web.xml
+++ b/war/WEB-INF/appengine-web.xml
@@ -2,6 +2,7 @@
 <appengine-web-app xmlns="http://appengine.google.com/ns/1.0">
   <application></application>
   <version>1</version>
+  <sessions-enabled>true</sessions-enabled>
 
   <!--
     Allows App Engine to send multiple requests to one instance in parallel: