diff --git a/docker-compose.yml b/docker-compose.yml
index ac2a1c3..8a86d91 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -88,7 +88,7 @@ services:
 
     redis:
         restart: always
-        image: redis
+        image: redis:5.0.0
         container_name: redis
         # modify to get rid of the redis issue #35 and #19 with a better solution
         # WARNING: /proc/sys/net/core/somaxconn is set to the lower value of 128.
diff --git a/ldap-overleaf-sl/sharelatex/AuthenticationManager.js b/ldap-overleaf-sl/sharelatex/AuthenticationManager.js
index ba7ba06..e5213e9 100644
--- a/ldap-overleaf-sl/sharelatex/AuthenticationManager.js
+++ b/ldap-overleaf-sl/sharelatex/AuthenticationManager.js
@@ -212,7 +212,7 @@ const AuthenticationManager = {
             }
             db.users.update(
                 {
-                    _id: ObjectId(userId.toString())
+                    _id: ObjectId(userId._id.toString())
                 },
                 {
                     $set: {