diff --git a/tools/releasetools/ota_utils.py b/tools/releasetools/ota_utils.py
index e36a2be..9f41874 100644
--- a/tools/releasetools/ota_utils.py
+++ b/tools/releasetools/ota_utils.py
@@ -22,7 +22,7 @@
 
 import ota_metadata_pb2
 import common
-from common import (ZipDelete, OPTIONS, MakeTempFile,
+from common import (ZipDelete, ZipClose, OPTIONS, MakeTempFile,
                     ZipWriteStr, BuildInfo, LoadDictionaryFromFile,
                     SignFile, PARTITIONS_WITH_BUILD_PROP, PartitionBuildProps,
                     GetRamdiskFormat)