diff --git a/shared/data_store/get_image.py b/shared/data_store/get_image.py
index 0459aab..e61a2ff 100644
--- a/shared/data_store/get_image.py
+++ b/shared/data_store/get_image.py
@@ -15,6 +15,7 @@ def get_image(
     """Get image from image subfolder in bucket in Minio."""
     assert isinstance(client, Minio)
     assert isinstance(object_name, str)
+    assert len(object_name) > 0
     # prepare arguments
     bucket_name = os.getenv('MINIO_BUCKET_NAME')
     subfolder = 'images'