diff --git a/skimage/filters/tests/test_filter_import.py b/skimage/filters/tests/test_filter_import.py
index ffe9d7d7..133ad262 100644
--- a/skimage/filters/tests/test_filter_import.py
+++ b/skimage/filters/tests/test_filter_import.py
@@ -8,4 +8,4 @@ def test_filter_import():
 
     assert('sobel' in dir(F))
     assert any(['has been renamed' in w
-                for (w, _, _) in F.__warningregistry__])
+                for (w, _, _) in F.__warningregistry__]), F.__warningregistry__