Fix instance check, on some versions of Python

1 files changed, 1 insertions, 2 deletions

diff --git a/pies/_utils.py b/pies/_utils.py
index f8937ae..f64b6b6 100644
--- a/pies/_utils.py
+++ b/pies/_utils.py
@@ -54,11 +54,10 @@ def unmodified_isinstance(*bases):
         it allows calls against passed in built in instances to pass even if there not a subclass
     """
     class UnmodifiedIsInstance(type):
+        @classmethod
         def __instancecheck__(cls, instance):
             if cls.__name__ in (str(base.__name__) for base in bases):
                 return isinstance(instance, bases)
             return type.__instancecheck__(cls, instance)
 
-            return isinstance(instance, bases)
-
     return with_metaclass(UnmodifiedIsInstance, *bases)