diff --git a/pySim/card_key_provider.py b/pySim/card_key_provider.py
index 66e96e9d..0827b70f 100644
--- a/pySim/card_key_provider.py
+++ b/pySim/card_key_provider.py
@@ -173,9 +173,6 @@ class CardKeyProvider(abc.ABC):
 class CardKeyProviderCsv(CardKeyProvider):
     """Card key provider implementation that allows to query against a specified CSV file."""
 
-    csv_file = None
-    filename = None
-
     def __init__(self, csv_filename: str, transport_keys: dict):
         """
         Args: