diff --git a/splunklib/ai/base_agent.py b/splunklib/ai/base_agent.py
index 3e9de535..596d452e 100644
--- a/splunklib/ai/base_agent.py
+++ b/splunklib/ai/base_agent.py
@@ -94,9 +94,9 @@ def __init__(
         ]
 
         self._middleware = (
-            *{m for m in predefined_before if type(m) not in user_middleware_types},
+            *[m for m in predefined_before if type(m) not in user_middleware_types],
             *user_middleware,
-            *{m for m in predefined_after if type(m) not in user_middleware_types},
+            *[m for m in predefined_after if type(m) not in user_middleware_types],
         )
 
         self._trace_id = secrets.token_hex(16)  # 32 Hex characters
diff --git a/tests/unit/ai/test_default_limits.py b/tests/unit/ai/test_default_limits.py
index 66957f8d..714a58b2 100644
--- a/tests/unit/ai/test_default_limits.py
+++ b/tests/unit/ai/test_default_limits.py
@@ -26,6 +26,7 @@
     TimeoutLimitMiddleware,
     TokenLimitExceededException,
     TokenLimitMiddleware,
+    StructuredOutputRetryLimitMiddleware,
 )
 from splunklib.ai.messages import AIMessage, AgentResponse
 from splunklib.ai.middleware import AgentMiddleware, AgentRequest, AgentState, ModelRequest, ModelResponse
@@ -173,3 +174,12 @@ async def test_raises_when_steps_in_request_reach_limit(self) -> None:
         await mw.model_middleware(_make_model_request(total_steps=2), _noop_model_handler)
         with self.assertRaises(StepsLimitExceededException):
             await mw.model_middleware(_make_model_request(total_steps=3), _noop_model_handler)
+
+
+def test_default_middleware() -> None:
+    agent = _make_agent()
+    mw = list(agent.middleware or [])
+    assert isinstance(mw[0], StructuredOutputRetryLimitMiddleware)
+    assert isinstance(mw[1], TokenLimitMiddleware)
+    assert isinstance(mw[2], StepLimitMiddleware)
+    assert isinstance(mw[3], TimeoutLimitMiddleware)