diff --git a/src/cal_tools/agipdlib.py b/src/cal_tools/agipdlib.py
index d2a6bbed351fd6c56afb673a01998dc1c070b4ba..7ab0087deb9f200b9756854f172d51c698142abf 100644
--- a/src/cal_tools/agipdlib.py
+++ b/src/cal_tools/agipdlib.py
@@ -1415,12 +1415,14 @@ class AgipdCorrections:
             # to skip correcting this module.
             return
 
-    def initialize_from_db(self, karabo_id: str, karabo_da: str,
-                           creation_time: datetime, memory_cells: float,
-                           bias_voltage: int, gain_setting: int,
-                           acquisition_rate: float, gain_mode: int,
-                           integration_time: int, module_idx: int,
-                           photon_energy: float = 9.2, client = None,
+    def initialize_from_db(
+        self, karabo_id: str, karabo_da: str,
+        creation_time: datetime, memory_cells: float,
+        bias_voltage: int, gain_setting: int,
+        acquisition_rate: float, gain_mode: int,
+        integration_time: int, module_idx: int,
+        photon_energy: float = 9.2,
+        client: "calibration_client.CalibrationClient" = None,  # noqa
     ):
         """ Initialize calibration constants from the calibration database