diff --git a/backend/tests/test_lead_agent_model_resolution.py b/backend/tests/test_lead_agent_model_resolution.py
index 437c6cd83..4a5f22e5f 100644
--- a/backend/tests/test_lead_agent_model_resolution.py
+++ b/backend/tests/test_lead_agent_model_resolution.py
@@ -81,7 +81,7 @@ def test_make_lead_agent_disables_thinking_when_model_does_not_support_it(monkey
 
     captured: dict[str, object] = {}
 
-    def _fake_create_chat_model(*, name, thinking_enabled, reasoning_effort=None):
+    def _fake_create_chat_model(*, name, thinking_enabled, reasoning_effort=None, app_config=None):
         captured["name"] = name
         captured["thinking_enabled"] = thinking_enabled
         captured["reasoning_effort"] = reasoning_effort
@@ -146,7 +146,7 @@ def test_create_summarization_middleware_uses_configured_model_alias(monkeypatch
     fake_model = MagicMock()
     fake_model.with_config.return_value = fake_model
 
-    def _fake_create_chat_model(*, name=None, thinking_enabled, reasoning_effort=None):
+    def _fake_create_chat_model(*, name=None, thinking_enabled, reasoning_effort=None, app_config=None):
         captured["name"] = name
         captured["thinking_enabled"] = thinking_enabled
         captured["reasoning_effort"] = reasoning_effort