diff --git a/backend/project/endpoints/projects/project_assignment_file.py b/backend/project/endpoints/projects/project_assignment_file.py
index bc360c3d..9bdc5b11 100644
--- a/backend/project/endpoints/projects/project_assignment_file.py
+++ b/backend/project/endpoints/projects/project_assignment_file.py
@@ -25,7 +25,7 @@ def get(self, project_id):
 
         project = Project.query.filter(getattr(Project, "project_id") == project_id).first()
 
-        file_url = urljoin(f"{UPLOAD_FOLDER}", f"{project_id}") + "/"
+        file_url = safe_join(f"{UPLOAD_FOLDER}", f"{project_id}")
 
         directory = safe_join(os.getcwd(), file_url)