diff --git a/codex-rs/core/src/tools/handlers/multi_agents_tests.rs b/codex-rs/core/src/tools/handlers/multi_agents_tests.rs
index 6b8f800d41..9f57674552 100644
--- a/codex-rs/core/src/tools/handlers/multi_agents_tests.rs
+++ b/codex-rs/core/src/tools/handlers/multi_agents_tests.rs
@@ -377,7 +377,7 @@ async fn multi_agent_v2_spawn_fork_turns_ignores_child_model_overrides() {
             Arc::new(turn),
             "spawn_agent",
             function_payload(json!({
-                "message": "inspect this repo",
+                "items": [{"type": "text", "text": "inspect this repo"}],
                 "model": "not-a-real-model",
                 "reasoning_effort": "low",
                 "fork_turns": "all",