diff --git a/shiftregister/app/sipgate/history.py b/shiftregister/app/sipgate/history.py
index 46d6274..c2d050f 100644
--- a/shiftregister/app/sipgate/history.py
+++ b/shiftregister/app/sipgate/history.py
@@ -14,7 +14,7 @@ class SMS:
         self.sender = item["source"]
 
 
-def list_incoming_sms(from_date=None):
+def list_incoming_sms(from_dt=None):
     if not settings.SIPGATE_INCOMING_TOKEN_ID:
         raise RuntimeError("required setting SIPGATE_INCOMING_TOKEN_ID is not set")
 
@@ -28,7 +28,7 @@ def list_incoming_sms(from_date=None):
         "types": "SMS",
     }
 
-    if from_date is not None:
+    if from_dt is not None:
         params["from"] = (
             from_dt.astimezone(timezone.utc).isoformat(timespec="seconds") + "Z"
         )