diff --git a/src/py_moodle/draftfile.py b/src/py_moodle/draftfile.py
index 3d3de9a..0e0e617 100644
--- a/src/py_moodle/draftfile.py
+++ b/src/py_moodle/draftfile.py
@@ -123,7 +123,12 @@ def detect_upload_repo(session: requests.Session, base_url: str, course_id: int)
 
     for repo_data in repositories.values():
         if repo_data.get("type") == "upload":
-            return int(repo_data["id"])
+            repo_id = int(repo_data["id"])
+            if repo_id <= 0:
+                raise MoodleDraftFileError(
+                    f"Invalid repository ID detected: {repo_id}. Repository ID must be a positive integer."
+                )
+            return repo_id
 
     raise MoodleDraftFileError(
         "No repository with type='upload' found in the configuration."
diff --git a/tests/test_draftfile.py b/tests/test_draftfile.py
index 30afbb5..cfc0b23 100644
--- a/tests/test_draftfile.py
+++ b/tests/test_draftfile.py
@@ -145,12 +145,9 @@ def test_detect_upload_repo_scraping(moodle, request, temporary_course_for_draft
             session=moodle, base_url=base_url, course_id=course_id
         )
 
-        # 1. Verify that the result is an integer
+        # Verify that the result is a positive integer
         assert isinstance(repo_id, int), "The returned repo_id should be an integer."
-
-        # 2. In a standard Moodle installation, the upload repository ID is 5.
-        #    This is a good check to ensure we are not getting a random value.
-        assert repo_id == 5, "The detected repo_id for 'upload' should typically be 5."
+        assert repo_id > 0, "The detected repo_id should be a positive integer."
 
     except MoodleDraftFileError as e:
         pytest.fail(f"detect_upload_repo failed with an exception: {e}")