diff --git a/six.py b/six.py
index 89b2188fd..47ecf52bd 100644
--- a/six.py
+++ b/six.py
@@ -637,6 +637,7 @@ def u(s):
     import io
     StringIO = io.StringIO
     BytesIO = io.BytesIO
+    del io
     _assertCountEqual = "assertCountEqual"
     if sys.version_info[1] <= 1:
         _assertRaisesRegex = "assertRaisesRegexp"