pyderasn.py | 5 ++++-

diff --git a/pyderasn.py b/pyderasn.py
index e241177c3fbb7667d6fb1ad41d2cbea8fb486207f4d7107ed11081079b725f9c..d41b0a4b4bbe51a385eb564c86807e4d8c83e4be9e8e4a7b1cb5e97bb049e610 100755
--- a/pyderasn.py
+++ b/pyderasn.py
@@ -3355,7 +3355,10 @@     def _value_sanitize(self, value):
         if isinstance(value, self.__class__):
             value = value._value
         elif isinstance(value, integer_types):
-            if value not in list(self.specs.values()):
+            for _value in self.specs.values():
+                if _value == value:
+                    break
+            else:
                 raise DecodeError(
                     "unknown integer value: %s" % value,
                     klass=self.__class__,