diff --git a/src/spikeinterface/preprocessing/unsigned_to_signed.py b/src/spikeinterface/preprocessing/unsigned_to_signed.py
index fdb5a663b1..402525aaf4 100644
--- a/src/spikeinterface/preprocessing/unsigned_to_signed.py
+++ b/src/spikeinterface/preprocessing/unsigned_to_signed.py
@@ -39,6 +39,7 @@ def __init__(
 
         self._kwargs = dict(
             recording=recording,
+            bit_depth=bit_depth,
         )