diff --git a/scripts/models.json b/scripts/models.json
index 5d1e800..f225bf9 100644
--- a/scripts/models.json
+++ b/scripts/models.json
@@ -3,7 +3,7 @@
   "roles": {
     "orchestrator": { "model": "claude-opus-5", "effort": "high" },
     "spec_author": { "model": "gpt-5.6-sol", "effort": "high" },
-    "utility_subagent": { "model": "claude-sonnet-4-6", "effort": "default" },
+    "utility_subagent": { "model": "gpt-5.6-luna", "effort": "default" },
     "worker": { "model": "gpt-5.6-luna", "effort": "high" },
     "bound_reviewer": { "model": "gpt-5.6-sol", "effort": "high" },
     "orchestrator_artifact_reviewer": { "model": "gpt-5.6-sol", "effort": "high" }