--- a/testing/mozharness/mozharness/mozilla/buildbot.py
+++ b/testing/mozharness/mozharness/mozilla/buildbot.py
@@ -63,17 +63,17 @@ class BuildbotMixin(object):
             # TODO try/except?
             self.buildbot_config = parse_config_file(c['buildbot_json_path'])
             buildbot_properties = copy.deepcopy(self.buildbot_config.get('properties', {}))
             if 'commit_titles' in buildbot_properties:
                 # Remove the commit messages since they can cause false positives with
                 # Treeherder log parsers. Eg: "Bug X - Fix TEST-UNEPXECTED-FAIL ...".
                 del buildbot_properties['commit_titles']
             self.info("Using buildbot properties:")
-            self.info(json.dumps(buildbot_properties, indent=4))
+            self.info(json.dumps(buildbot_properties, indent=4, sort_keys=True))
 
     def tryserver_email(self):
         pass
 
     def buildbot_status(self, tbpl_status, level=None, set_return_code=True):
         if tbpl_status not in TBPL_STATUS_DICT:
             self.error("buildbot_status() doesn't grok the status %s!" % tbpl_status)
         else: