diff --git a/prob2020/python/permutation.py b/prob2020/python/permutation.py
index 959d5e7..e79922d 100644
--- a/prob2020/python/permutation.py
+++ b/prob2020/python/permutation.py
@@ -3,7 +3,6 @@
 from ..cython import cutils
 import prob2020.python.mutation_context as mc
 import prob2020.python.scores as scores
-import IPython
 
 
 def deleterious_permutation(obs_del,