diff --git a/shared/data_store/get_image.py b/shared/data_store/get_image.py
index e61a2ff..87a0bc5 100644
--- a/shared/data_store/get_image.py
+++ b/shared/data_store/get_image.py
@@ -17,6 +17,7 @@ def get_image(
     assert isinstance(object_name, str)
     assert len(object_name) > 0
     # prepare arguments
+    assert 'MINIO_BUCKET_NAME' in os.environ
     bucket_name = os.getenv('MINIO_BUCKET_NAME')
     subfolder = 'images'
     # get object from bucket