diff --git a/freqtrade/rpc/rpc.py b/freqtrade/rpc/rpc.py
index 5b78c8356..048ebec63 100644
--- a/freqtrade/rpc/rpc.py
+++ b/freqtrade/rpc/rpc.py
@@ -470,7 +470,7 @@ class RPC(object):
                }
         return res
 
-    def _rpc_blacklist(self, add: List[str]) -> Dict:
+    def _rpc_blacklist(self, add: List[str] = None) -> Dict:
         """ Returns the currently active blacklist"""
         if add:
             stake_currency = self._freqtrade.config.get('stake_currency')