diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index ca4581e..1bb311c 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -3,3 +3,4 @@ repos:
     rev: 1.3.1 # The version of Prospector to use, at least 1.1.7
     hooks:
     -   id: prospector
+        language: system
diff --git a/libs/oauth.py b/libs/oauth.py
index 5698147..f2445a7 100644
--- a/libs/oauth.py
+++ b/libs/oauth.py
@@ -75,3 +75,4 @@ class OauthAPIClient(ApiClient):
                     self.configuration.refresh_callback()
                 else:
                     raise e
+        return None
diff --git a/my_psacc.py b/my_psacc.py
index db25e36..6aa36ea 100644
--- a/my_psacc.py
+++ b/my_psacc.py
@@ -331,6 +331,7 @@ class MyPSACC:
         except IndexError:
             logger.error(traceback.format_exc())
             logger.error("Can't get charge hour: %s", hour_str)
+            return None
 
     def get_charge_status(self, vin):
         data = self.get_vehicle_info(vin)
diff --git a/otp/otp.py b/otp/otp.py
index 37f6bd7..617d879 100644
--- a/otp/otp.py
+++ b/otp/otp.py
@@ -16,6 +16,7 @@ from mylogger import logger
 from . import oaep
 from .load import IWData
 
+
 # pylint: disable=too-many-instance-attributes,invalid-name
 
 def etree_to_dict(t):
@@ -169,7 +170,7 @@ class Otp:
             return etree_to_dict(ElT.XML(raw_xml))["ActionFinalize"]
         except KeyError:
             logger.debug(raw_xml)
-            raise ValueError("Bad response from server")
+            raise ValueError("Bad response from server") from KeyError
 
     def activation_start(self):
         param = {"action": "ActionSetup", "mode": self.mode, "id": self.data.iwid, "lastsync": self.data.iwTsync,
@@ -214,7 +215,7 @@ class Otp:
             try:
                 self.defi = str(xml["defi"])
             except KeyError:
-                raise ConfigException
+                raise ConfigException from KeyError
             if "J" in xml:
                 logger.debug("Need another otp request")
                 return Otp.OTP_TWICE
@@ -301,10 +302,24 @@ def save_otp(obj, filename="otp.bin"):
         pickle.dump(obj, output)
 
 
+class RenameUnpickler(pickle.Unpickler):
+    def find_class(self, module, name):
+        renamed_module = module
+        if module == 'otp.Otp':
+            renamed_module = "otp.otp"
+        elif module == 'otp.Tokenizer':
+            renamed_module = "otp.tokenizer"
+
+        return super().find_class(renamed_module, name)
+
+
 def load_otp(filename="otp.bin"):
     try:
         with open(filename, 'rb') as input_file:
-            return pickle.load(input_file)
+            try:
+                return pickle.load(input_file)
+            except ModuleNotFoundError:
+                return RenameUnpickler(input_file).load()
     except FileNotFoundError:
         logger.debug(traceback.format_exc())
     return None