diff --git a/api/ble.py b/api/ble.py
index 16f3601..ab40541 100644
--- a/api/ble.py
+++ b/api/ble.py
@@ -268,7 +268,7 @@ def sensor_data_query(mac_list: List[str]) -> List[dict]:
 
 def test(test_count = 0, bt_usb_id = None) -> None:
     # first test scanner
-    if bt_usb_id = None:
+    if bt_usb_id == None:
         log.error(f"Error - no USB ID Passed, this is needed for the test")
         return -1