pyderasn.py | 3 +++

diff --git a/pyderasn.py b/pyderasn.py
index 145702046d9496269deb17a38c7578ce2edcef9c1a51eb385f0ed4dcea7187f4..718c657ace759810195ae5632816b1d1725cde042f104d0d71dd80129dbb6588 100755
--- a/pyderasn.py
+++ b/pyderasn.py
@@ -1,6 +1,8 @@
 #!/usr/bin/env python
 # coding: utf-8
 # cython: language_level=3
+# pylint: disable=line-too-long,superfluous-parens,protected-access,too-many-lines
+# pylint: disable=too-many-return-statements,too-many-branches,too-many-statements
 # PyDERASN -- Python ASN.1 DER/CER/BER codec with abstract structures
 # Copyright (C) 2017-2020 Sergey Matveev <stargrave@stargrave.org>
 #
@@ -4970,6 +4972,7 @@             value = self._value.isoformat()
             if self.ber_encoded:
                 value += " (%s)" % self.ber_raw
             return value
+        return None
 
     def __unicode__(self):
         if self.ready: