diff --git a/phoenix_bec/devices/unsupported_legacy/psi_detector_base.py b/phoenix_bec/devices/unsupported_legacy/psi_detector_base.py
index 8744fec..29f3322 100644
--- a/phoenix_bec/devices/unsupported_legacy/psi_detector_base.py
+++ b/phoenix_bec/devices/unsupported_legacy/psi_detector_base.py
@@ -326,7 +326,7 @@ class PSIDetectorBase(Device):
     (https://bec.readthedocs.io/en/latest/) for more information about device integration.
     """
 
-    custom_prepare_cls =        
+    custom_prepare_cls = CustomDetectorMixin     
 
     filepath = Cpt(SetableSignal, value="", kind=Kind.config)