diff --git a/src/allmydata/storage/immutable.py b/src/allmydata/storage/immutable.py
index 4f6a1c9c7..8a7a5a966 100644
--- a/src/allmydata/storage/immutable.py
+++ b/src/allmydata/storage/immutable.py
@@ -24,7 +24,6 @@ from allmydata.interfaces import (
 )
 from allmydata.util import base32, fileutil, log
 from allmydata.util.assertutil import precondition
-from allmydata.util.hashutil import timing_safe_compare
 from allmydata.storage.lease import LeaseInfo
 from allmydata.storage.common import UnknownImmutableContainerVersionError