diff --git a/src/api/authentication.py b/src/api/authentication.py
index 364be95e598919fc83723233944816962bb0409a..1a358506cb83f5fa84c1ebf2ac1c75c3c3528db9 100644
--- a/src/api/authentication.py
+++ b/src/api/authentication.py
@@ -321,7 +321,7 @@ def is_authenticated(auth_list: [], for_lecture: bool):
                 return True
             
             for moodle_id in perm.moodle_course_ids:
-                if moodle_id in session.get("moodle_courses", []):
+                if str(moodle_id) in session.get("moodle_courses", []):
                     return True
             
             if "auth_data" in session: