diff --git a/core/admin/mailu/utils.py b/core/admin/mailu/utils.py
index 972546d6..8ae028bf 100644
--- a/core/admin/mailu/utils.py
+++ b/core/admin/mailu/utils.py
@@ -269,7 +269,7 @@ class MailuSession(CallbackDict, SessionMixin):
 
         # set uid from dict data
         if self._uid is None:
-            self._uid = self.app.session_config.gen_uid(self.get('user_id', ''))
+            self._uid = self.app.session_config.gen_uid(self.get('_user_id', ''))
 
         # create new session id for new or regenerated sessions and force setting the cookie
         if self._sid is None:
diff --git a/core/admin/requirements-prod.txt b/core/admin/requirements-prod.txt
index 4a209fba..bb94e4b5 100644
--- a/core/admin/requirements-prod.txt
+++ b/core/admin/requirements-prod.txt
@@ -22,7 +22,7 @@ Flask-Babel==1.0.0
 Flask-Bootstrap==3.3.7.1
 Flask-DebugToolbar==0.10.1
 Flask-Limiter==1.0.1
-Flask-Login==0.4.1
+Flask-Login==0.5.0
 flask-marshmallow==0.14.0
 Flask-Migrate==3.1.0
 Flask-Script==2.0.6