diff --git a/blackbox/bwc/create_bwc_index.py b/blackbox/bwc/create_bwc_index.py
index e28fe245d33d..b1430f4908b8 100644
--- a/blackbox/bwc/create_bwc_index.py
+++ b/blackbox/bwc/create_bwc_index.py
@@ -35,9 +35,8 @@ def compress(data_dir, output_dir, target):
     target = os.path.join(abs_output_dir, target)
     if os.path.exists(target):
         os.remove(target)
-    zipf = zipfile.ZipFile(target, 'w', zipfile.ZIP_DEFLATED)
-    zipdir(data_dir, zipf, os.path.dirname(data_dir))
-    zipf.close()
+    with zipfile.ZipFile(target, 'w', zipfile.ZIP_DEFLATED) as zipf:
+        zipdir(data_dir, zipf, os.path.dirname(data_dir))
 
 
 def zipdir(path, ziph, basePath):