diff --git a/tests/test_spawner.py b/tests/test_spawner.py
index 6de23d7..6eabe8c 100644
--- a/tests/test_spawner.py
+++ b/tests/test_spawner.py
@@ -219,10 +219,11 @@ class TestAcquireFirst:
     def test_phase1_counter_acquire_exclusive(self, spawner):
         """E11.3 Phase 1: counter acquire 互斥
 
-        同一 agent 并发 spawn → 第二个 AgentBusyError(reason=counter_blocked)。
+        同一 agent 并发 spawn → 第二个 AgentBusyError(reason 含 counter)。
+        使用 max_concurrent_sessions=1 确保同 agent 第二次 acquire 失败。
         """
         from src.daemon.counter import ActiveAgentCounter
-        counter = ActiveAgentCounter(max_global=5, max_per_agent=1)
+        counter = ActiveAgentCounter(max_global=5, max_concurrent_sessions=1)
         spawner.counter = counter
 
         # 第一次 acquire 成功
@@ -231,7 +232,7 @@ class TestAcquireFirst:
         )
         assert session_id
 
-        # 第二次 acquire → counter_blocked
+        # 第二次 acquire → counter blocked（同 agent 已有活跃 session）
         with pytest.raises(AgentBusyError) as exc_info:
             asyncio.run(
                 spawner.spawn_full_agent("test-agent", "task2", task_id="t2")