diff --git a/product/ERP5/bootstrap/erp5_core/SkinTemplateItem/portal_skins/erp5_auto_logout/logout.py b/product/ERP5/bootstrap/erp5_core/SkinTemplateItem/portal_skins/erp5_auto_logout/logout.py
index 562258fbf909c4f2347fc17851ad92b44c6fdf95..67811176144f662d212931f05fec3e2a07a0c107 100644
--- a/product/ERP5/bootstrap/erp5_core/SkinTemplateItem/portal_skins/erp5_auto_logout/logout.py
+++ b/product/ERP5/bootstrap/erp5_core/SkinTemplateItem/portal_skins/erp5_auto_logout/logout.py
@@ -1,10 +1,12 @@
 from AccessControl import getSecurityManager
 portal = context.getPortalObject()
-portal.portal_sessions.manage_delObjects(
-  portal.Base_getAutoLogoutSessionKey(
-    username=getSecurityManager().getUser().getUserName(),
+username = getSecurityManager().getUser().getUserName()
+if username is not None:
+  portal.portal_sessions.manage_delObjects(
+    portal.Base_getAutoLogoutSessionKey(
+      username=username,
+    )
   )
-)
 REQUEST = portal.REQUEST
 if REQUEST.has_key('portal_skin'):
   portal.portal_skins.clearSkinCookie()