diff --git a/tests/test_pydantic_v1_deprecation_warnings.py b/tests/test_pydantic_v1_deprecation_warnings.py
index 00694c906..e0008e218 100644
--- a/tests/test_pydantic_v1_deprecation_warnings.py
+++ b/tests/test_pydantic_v1_deprecation_warnings.py
@@ -9,6 +9,7 @@ if sys.version_info >= (3, 14):
 
 from fastapi import FastAPI
 from fastapi._compat.v1 import BaseModel
+from fastapi.testclient import TestClient
 
 
 def test_warns_pydantic_v1_model_in_endpoint_param() -> None:
@@ -26,6 +27,11 @@ def test_warns_pydantic_v1_model_in_endpoint_param() -> None:
         def endpoint(data: ParamModelV1):
             return data
 
+    client = TestClient(app)
+    response = client.post("/param", json={"name": "test"})
+    assert response.status_code == 200, response.text
+    assert response.json() == {"name": "test"}
+
 
 def test_warns_pydantic_v1_model_in_return_type() -> None:
     class ReturnModelV1(BaseModel):
@@ -42,6 +48,11 @@ def test_warns_pydantic_v1_model_in_return_type() -> None:
         def endpoint() -> ReturnModelV1:
             return ReturnModelV1(name="test")
 
+    client = TestClient(app)
+    response = client.get("/return")
+    assert response.status_code == 200, response.text
+    assert response.json() == {"name": "test"}
+
 
 def test_warns_pydantic_v1_model_in_response_model() -> None:
     class ResponseModelV1(BaseModel):
@@ -58,6 +69,11 @@ def test_warns_pydantic_v1_model_in_response_model() -> None:
         def endpoint():
             return {"name": "test"}
 
+    client = TestClient(app)
+    response = client.get("/response-model")
+    assert response.status_code == 200, response.text
+    assert response.json() == {"name": "test"}
+
 
 def test_warns_pydantic_v1_model_in_additional_responses_model() -> None:
     class ErrorModelV1(BaseModel):
@@ -75,3 +91,8 @@ def test_warns_pydantic_v1_model_in_additional_responses_model() -> None:
         )
         def endpoint():
             return {"ok": True}
+
+    client = TestClient(app)
+    response = client.get("/responses")
+    assert response.status_code == 200, response.text
+    assert response.json() == {"ok": True}