diff --git a/src/zennit/types.py b/src/zennit/types.py
index 33cdd30..bb5bed9 100644
--- a/src/zennit/types.py
+++ b/src/zennit/types.py
@@ -19,6 +19,7 @@
 import torch
 import torchvision
 
+
 class SubclassMeta(type):
     '''Meta class to bundle multiple subclasses.'''
     def __instancecheck__(cls, inst):