diff --git a/openedx/core/djangoapps/catalog/utils.py b/openedx/core/djangoapps/catalog/utils.py
index 3743697ed7..8ca8de5ce9 100644
--- a/openedx/core/djangoapps/catalog/utils.py
+++ b/openedx/core/djangoapps/catalog/utils.py
@@ -324,7 +324,7 @@ def get_fulfillable_course_runs_for_entitlement(entitlement, course_runs):
     search_time = datetime.datetime.now(UTC)
     for course_run in course_runs:
         course_id = CourseKey.from_string(course_run.get('key'))
-        is_enrolled = CourseEnrollment.is_enrolled(entitlement.user, str(course_id))
+        is_enrolled = CourseEnrollment.is_enrolled(entitlement.user, course_id)
         if is_course_run_entitlement_fullfillable(course_id, entitlement, search_time) and not is_enrolled:
             enrollable_sessions.append(course_run)