diff --git a/api/ble.py b/api/ble.py
index 3ef8055..068f00a 100644
--- a/api/ble.py
+++ b/api/ble.py
@@ -209,7 +209,7 @@ def sensor_data_query(mac_list: List[str]) -> List[dict]:
         except Exception as e:
             print(f"Error reading BLE data - {e}")
             this_result = None
-        if "org.freedesktop.DBus.Error.AccessDenied" in e and e:
+        if e and "org.freedesktop.DBus.Error.AccessDenied" in e:
             return result
         if this_result:
             result.append(