diff --git a/debian/50gnm.py b/debian/50gnm.py
index df2ba0f..1b7df01 100644
--- a/debian/50gnm.py
+++ b/debian/50gnm.py
@@ -564,3 +564,5 @@ WCS_FORM_ASSET_SLOTS = {
 
 import memcache
 memcache.SERVER_MAX_VALUE_LENGTH = 10 * 1024 * 1024
+
+SESSION_EXPIRE_AT_BROWSER_CLOSE = False