diff --git a/skimage/_shared/_warnings.py b/skimage/_shared/_warnings.py
index 99f2de0f..72de07b7 100644
--- a/skimage/_shared/_warnings.py
+++ b/skimage/_shared/_warnings.py
@@ -5,6 +5,7 @@ import sys
 import warnings
 import inspect
 
+
 @contextmanager
 def all_warnings():
     """