diff --git a/tests/unit/pydantic_ai_lightspeed/capabilities/redaction/test_capability.py b/tests/unit/pydantic_ai_lightspeed/capabilities/redaction/test_capability.py
index cc7f6fe68..0307312df 100644
--- a/tests/unit/pydantic_ai_lightspeed/capabilities/redaction/test_capability.py
+++ b/tests/unit/pydantic_ai_lightspeed/capabilities/redaction/test_capability.py
@@ -268,7 +268,9 @@ async def test_before_model_request_no_match(
         )
         result = await capability.before_model_request(mocker.Mock(), request_context)
         assert result is request_context
-        assert req.parts[0].content == "safe text"
+        part = req.parts[0]
+        assert isinstance(part, UserPromptPart)
+        assert part.content == "safe text"
 
     @pytest.mark.asyncio()
     async def test_after_model_request_redacts_response(