diff --git a/_pytest/assertion/rewrite.py b/_pytest/assertion/rewrite.py
index cf295ef1b..97eeb6623 100644
--- a/_pytest/assertion/rewrite.py
+++ b/_pytest/assertion/rewrite.py
@@ -1,7 +1,6 @@
 """Rewrite assertion AST to produce nice error messages"""
 
 import ast
-import collections
 import errno
 import itertools
 import imp