--- a/taskcluster/taskgraph/transforms/task.py
+++ b/taskcluster/taskgraph/transforms/task.py
@@ -785,17 +785,18 @@ def build_docker_worker_payload(config, 
         features['chainOfTrust'] = True
 
     if worker.get('docker-in-docker'):
         features['dind'] = True
 
     if task.get('needs-sccache'):
         features['taskclusterProxy'] = True
         task_def['scopes'].append(
-            'assume:project:taskcluster:level-{level}-sccache-buckets'.format(
+            'assume:project:taskcluster:{trust_domain}:level-{level}-sccache-buckets'.format(
+                trust_domain=config.graph_config['trust-domain'],
                 level=config.params['level'])
         )
         worker['env']['USE_SCCACHE'] = '1'
     else:
         worker['env']['SCCACHE_DISABLE'] = '1'
 
     capabilities = {}