diff --git a/src/openai/lib/_parsing/_responses.py b/src/openai/lib/_parsing/_responses.py
index 8853a0749f..b2dfb7c96c 100644
--- a/src/openai/lib/_parsing/_responses.py
+++ b/src/openai/lib/_parsing/_responses.py
@@ -1,7 +1,7 @@
 from __future__ import annotations
 
 import json
-from typing import TYPE_CHECKING, List, Iterable, cast
+from typing import TYPE_CHECKING, Any, List, Iterable, cast
 from typing_extensions import TypeVar, assert_never
 
 import pydantic
@@ -67,22 +67,28 @@ def parse_response(
                     continue
 
                 content_list.append(
-                    construct_type_unchecked(
-                        type_=ParsedResponseOutputText[TextFormatT],
-                        value={
-                            **item.to_dict(),
-                            "parsed": parse_text(item.text, text_format=text_format),
-                        },
+                    cast(
+                        Any,
+                        construct_type_unchecked(
+                            type_=ParsedResponseOutputText,
+                            value={
+                                **item.to_dict(),
+                                "parsed": parse_text(item.text, text_format=text_format),
+                            },
+                        ),
                     )
                 )
 
             output_list.append(
-                construct_type_unchecked(
-                    type_=ParsedResponseOutputMessage[TextFormatT],
-                    value={
-                        **output.to_dict(),
-                        "content": content_list,
-                    },
+                cast(
+                    Any,
+                    construct_type_unchecked(
+                        type_=ParsedResponseOutputMessage,
+                        value={
+                            **output.to_dict(),
+                            "content": content_list,
+                        },
+                    ),
                 )
             )
         elif output.type == "function_call":
@@ -129,12 +135,15 @@ def parse_response(
         else:
             output_list.append(output)
 
-    return construct_type_unchecked(
-        type_=ParsedResponse[TextFormatT],
-        value={
-            **response.to_dict(),
-            "output": output_list,
-        },
+    return cast(
+        ParsedResponse[TextFormatT],
+        construct_type_unchecked(
+            type_=ParsedResponse,
+            value={
+                **response.to_dict(),
+                "output": output_list,
+            },
+        ),
     )
 
 
diff --git a/tests/lib/responses/test_responses.py b/tests/lib/responses/test_responses.py
index 8e5f16df95..9c4dd54f3e 100644
--- a/tests/lib/responses/test_responses.py
+++ b/tests/lib/responses/test_responses.py
@@ -1,13 +1,22 @@
 from __future__ import annotations
 
+from typing import Any
 from typing_extensions import TypeVar
 
 import pytest
 from respx import MockRouter
 from inline_snapshot import snapshot
+from pydantic import BaseModel
 
 from openai import OpenAI, AsyncOpenAI
 from openai._utils import assert_signatures_in_sync
+from openai.types.responses import Response
+from openai.lib._parsing._responses import parse_response
+from openai.types.responses.parsed_response import (
+    ParsedResponse,
+    ParsedResponseOutputText,
+    ParsedResponseOutputMessage,
+)
 
 from ...conftest import base_url
 from ..snapshots import make_snapshot_request
@@ -61,3 +70,78 @@ def test_parse_method_definition_in_sync(sync: bool, client: OpenAI, async_clien
         checking_client.responses.parse,
         exclude_params={"tools"},
     )
+
+
+def test_parse_response_uses_non_parameterized_runtime_types(monkeypatch: pytest.MonkeyPatch) -> None:
+    class Payload(BaseModel):
+        message: str
+
+    response = Response.model_validate(
+        {
+            "id": "resp_123",
+            "object": "response",
+            "created_at": 0,
+            "status": "completed",
+            "background": False,
+            "error": None,
+            "incomplete_details": None,
+            "instructions": None,
+            "max_output_tokens": None,
+            "max_tool_calls": None,
+            "model": "gpt-4o-mini",
+            "output": [
+                {
+                    "id": "msg_123",
+                    "type": "message",
+                    "status": "completed",
+                    "role": "assistant",
+                    "content": [
+                        {
+                            "type": "output_text",
+                            "annotations": [],
+                            "logprobs": [],
+                            "text": '{"message":"hello"}',
+                        }
+                    ],
+                }
+            ],
+            "parallel_tool_calls": True,
+            "previous_response_id": None,
+            "prompt_cache_key": None,
+            "reasoning": {"effort": None, "summary": None},
+            "safety_identifier": None,
+            "service_tier": "default",
+            "store": True,
+            "temperature": 1.0,
+            "text": {"format": {"type": "text"}, "verbosity": "medium"},
+            "tool_choice": "auto",
+            "tools": [],
+            "top_logprobs": 0,
+            "top_p": 1.0,
+            "truncation": "disabled",
+            "usage": {
+                "input_tokens": 1,
+                "input_tokens_details": {"cached_tokens": 0},
+                "output_tokens": 1,
+                "output_tokens_details": {"reasoning_tokens": 0},
+                "total_tokens": 2,
+            },
+            "user": None,
+            "metadata": {},
+        }
+    )
+
+    seen_types: list[object] = []
+
+    def capture_construct_type_unchecked(*, value: object, type_: object) -> Any:
+        seen_types.append(type_)
+        from openai._models import construct_type_unchecked
+
+        return construct_type_unchecked(value=value, type_=type_)  # type: ignore[arg-type]
+
+    monkeypatch.setattr("openai.lib._parsing._responses.construct_type_unchecked", capture_construct_type_unchecked)
+
+    parsed = parse_response(text_format=Payload, input_tools=None, response=response)
+
+    assert parsed.output_parsed == Payload(message="hello")
+    assert seen_types == [ParsedResponseOutputText, ParsedResponseOutputMessage, ParsedResponse]