--- a/testing/taskcluster/mach_commands.py
+++ b/testing/taskcluster/mach_commands.py
@@ -407,22 +407,24 @@ class Graph(object):
                     build_parameters['build_slugid'],
                     build_task['task']['extra']['locations']['mozharness']
                 )
 
             build_url = ARTIFACT_URL.format(
                 build_parameters['build_slugid'],
                 build_task['task']['extra']['locations']['build']
             )
+            build_parameters['build_url'] = build_url
 
             # img_url is only necessary for device builds
             img_url = ARTIFACT_URL.format(
                 build_parameters['build_slugid'],
                 build_task['task']['extra']['locations'].get('img', '')
             )
+            build_parameters['img_url'] = img_url
 
             define_task = DEFINE_TASK.format(build_task['task']['workerType'])
 
             graph['scopes'].append(define_task)
             graph['scopes'].extend(build_task['task'].get('scopes', []))
             route_scopes = map(lambda route: 'queue:route:' + route, build_task['task'].get('routes', []))
             graph['scopes'].extend(route_scopes)
 
@@ -454,18 +456,16 @@ class Graph(object):
                                                      templates,
                                                      build_treeherder_config)
                 set_interactive_task(post_task, interactive)
                 graph['tasks'].append(post_task)
 
             for test in build['dependents']:
                 test = test['allowed_build_tasks'][build['task']]
                 test_parameters = copy.copy(build_parameters)
-                test_parameters['build_url'] = build_url
-                test_parameters['img_url'] = img_url
                 if tests_url:
                     test_parameters['tests_url'] = tests_url
                 if test_packages_url:
                     test_parameters['test_packages_url'] = test_packages_url
                 if mozharness_url:
                     test_parameters['mozharness_url'] = mozharness_url
                 test_definition = templates.load(test['task'], {})['task']
                 chunk_config = test_definition['extra']['chunks']