diff --git a/tests/test_spawner.py b/tests/test_spawner.py
index 98fd083..f4f774e 100644
--- a/tests/test_spawner.py
+++ b/tests/test_spawner.py
@@ -447,6 +447,31 @@ class TestAgentBusyErrorClassification:
             assert exc_info.value.detail is not None, \
                 f"Case {i}: expected detail to be set"
 
+    def test_session_running_in_blockers(self, spawner):
+        """session_running 出现在 blockers 列表中（session_locked 优先）
+
+        status=running + lock alive → session_locked 和 session_running 同时存在，
+        session_locked 排第一（primary_reason），但 blockers 列表包含 session_running。
+        """
+        spawner._check_session_state = lambda aid: {
+            "status": "running", "lock_pid_alive": True, "lock_expired": False,
+        }
+
+        with pytest.raises(AgentBusyError) as exc_info:
+            asyncio.run(
+                spawner.spawn_full_agent(
+                    "test-agent", "task",
+                    task_id="t1", use_main_session=True,
+                )
+            )
+        # primary_reason 是 session_locked
+        assert "session_locked" in exc_info.value.reason
+        # blockers 列表包含 session_running
+        blockers = exc_info.value.detail.get("blockers", [])
+        blocker_reasons = [b[0] for b in blockers]
+        assert "session_running" in blocker_reasons
+        assert "session_locked" in blocker_reasons
+
     def test_error_attributes(self):
         """E14 补充: AgentBusyError 属性验证"""
         err = AgentBusyError(