diff --git a/phoenix_bec/devices/unsupported_legacy/psi_detector_base.py b/phoenix_bec/devices/unsupported_legacy/psi_detector_base.py
index 1f76a4d..12a4b37 100644
--- a/phoenix_bec/devices/unsupported_legacy/psi_detector_base.py
+++ b/phoenix_bec/devices/unsupported_legacy/psi_detector_base.py
@@ -43,7 +43,7 @@ class CustomDetectorMixin:
     will allow the custom prepare class to access the parent device with all its signals.
     """
 
-    def __init__(self, *_args, parent: T = None, **_kwargs) -> None:
+    def __init__(self, *_args, parent = None, **_kwargs) -> None:
         """
         Initialize the custom prepare class.