diff --git a/Lib/test/test_zipfile.py b/Lib/test/test_zipfile.py
index bf7770b..87e99ec 100644
--- a/Lib/test/test_zipfile.py
+++ b/Lib/test/test_zipfile.py
@@ -1,3 +1,4 @@
+import zlib # implied prerequisite
 import zipfile, os, StringIO, tempfile
 from test_support import TestFailed