diff --git a/backend/app/students/routes/enrollments.py b/backend/app/students/routes/enrollments.py
index d92c91a..423f155 100644
--- a/backend/app/students/routes/enrollments.py
+++ b/backend/app/students/routes/enrollments.py
@@ -28,7 +28,7 @@ def assign_your_group_to_term_of_defence(examination_schedule_id: int, term_of_d
     if term_of_defence is None or ex is None:
         abort(400, "Term of defence not found!")
 
-    g = Group.query.join(ProjectSupervisor).filter(Group.year_group_id == examination_schedule_id). \
+    g = Group.query.join(ProjectSupervisor).filter(Group.year_group_id == ex.year_group_id). \
         join(Group.students).filter_by(index=student.index).first()
     if g is None or g.project_supervisor is None:
         abort(400, "You don't have a group or your group doesn't have an assigned project supervisor!")