diff --git a/kolla/image/build.py b/kolla/image/build.py
index 8cff137429..28e3afe59d 100755
--- a/kolla/image/build.py
+++ b/kolla/image/build.py
@@ -20,7 +20,6 @@ import errno
 import json
 import logging
 import os
-import pprint
 import re
 import requests
 import shutil
@@ -1025,7 +1024,7 @@ class KollaWorker(object):
 
         ancestry = {base.name: []}
         list_children(base.children, ancestry)
-        pprint.pprint(ancestry)
+        json.dump(ancestry, sys.stdout, indent=2)
 
     def find_parents(self):
         """Associate all images with parents and children."""
diff --git a/kolla/tests/test_build.py b/kolla/tests/test_build.py
index 0591fc127a..0c50db98ba 100644
--- a/kolla/tests/test_build.py
+++ b/kolla/tests/test_build.py
@@ -15,6 +15,7 @@ import itertools
 import mock
 import os
 import requests
+import sys
 
 from kolla.cmd import build as build_cmd
 from kolla import exception
@@ -352,14 +353,14 @@ class KollaWorkerTest(base.TestCase):
         self.assertRaises(ValueError,
                           kolla.filter_images)
 
-    @mock.patch('pprint.pprint')
-    def test_list_dependencies(self, pprint_mock):
+    @mock.patch('json.dump')
+    def test_list_dependencies(self, dump_mock):
         self.conf.set_override('profile', ['all'])
         kolla = build.KollaWorker(self.conf)
         kolla.images = self.images
         kolla.filter_images()
         kolla.list_dependencies()
-        pprint_mock.assert_called_once_with(mock.ANY)
+        dump_mock.assert_called_once_with(mock.ANY, sys.stdout, indent=2)
 
     def test_summary(self):
         kolla = build.KollaWorker(self.conf)