diff --git a/archive_util.py b/archive_util.py
--- a/archive_util.py
+++ b/archive_util.py
@@ -96,16 +96,18 @@
                  zip_filename, base_dir)
 
         if not dry_run:
-            z = zipfile.ZipFile(zip_filename, "w",
+            zip = zipfile.ZipFile(zip_filename, "w",
                                 compression=zipfile.ZIP_DEFLATED)
 
             for dirpath, dirnames, filenames in os.walk(base_dir):
+                dirnames.sort()
+                filenames.sort()
                 for name in filenames:
                     path = os.path.normpath(os.path.join(dirpath, name))
                     if os.path.isfile(path):
-                        z.write(path, path)
+                        zip.write(path, path)
                         log.info("adding '%s'" % path)
-            z.close()
+            zip.close()
 
     return zip_filename