diff --git a/tests/integration/contracts.json b/tests/integration/contracts.json
index d12e3ae4620..77c8916b8a8 100644
--- a/tests/integration/contracts.json
+++ b/tests/integration/contracts.json
@@ -1764,6 +1764,9 @@
     ],
     "tests/integration/mcp/test_mcp_lifecycle.py::test_same_url_server_grants_scope_discovery_and_direct_or_virtual_execution[bearer]": [
       "other.mcp.permissions.same_url_servers_enforce_discovery_and_execution"
+    ],
+    "tests/integration/providers/test_dashscope_chat_wire.py::test_dashscope_chat_forwards_reasoning_effort_none_to_the_provider": [
+      "other.provider_wire.dashscope.reasoning_effort_reaches_provider"
     ]
   },
   "browser": {
diff --git a/tests/integration/providers/test_dashscope_chat_wire.py b/tests/integration/providers/test_dashscope_chat_wire.py
new file mode 100644
index 00000000000..a2b3a36d6e3
--- /dev/null
+++ b/tests/integration/providers/test_dashscope_chat_wire.py
@@ -0,0 +1,62 @@
+import json
+import uuid
+from typing import Final
+
+import pytest
+from integration._support.client import Gateway
+from integration._support.wire import Reply, Request, wire_server
+from pydantic import JsonValue, TypeAdapter
+
+_BACKEND: Final = "qwen3.7-plus"
+_API_KEY: Final = "synthetic-dashscope-key"
+_PROMPT: Final = "What is 3^3?"
+_JSON_OBJECT: Final = TypeAdapter(dict[str, JsonValue])
+
+
+def _completion(identity: str) -> bytes:
+    return json.dumps(
+        {
+            "id": identity,
+            "object": "chat.completion",
+            "created": 1,
+            "model": _BACKEND,
+            "choices": [{"index": 0, "message": {"role": "assistant", "content": "27"}, "finish_reason": "stop"}],
+            "usage": {"prompt_tokens": 17, "completion_tokens": 5, "total_tokens": 22},
+        }
+    ).encode()
+
+
+@pytest.mark.covers("other.provider_wire.dashscope.reasoning_effort_reaches_provider")
+def test_dashscope_chat_forwards_reasoning_effort_none_to_the_provider(gateway: Gateway) -> None:
+    identity: Final = f"dashscope-reasoning-{uuid.uuid4().hex}"
+
+    def respond(request: Request) -> Reply:
+        assert request.method == "POST"
+        assert request.target == "/chat/completions"
+        assert request.headers["authorization"] == f"Bearer {_API_KEY}"
+        assert _JSON_OBJECT.validate_json(request.body) == {
+            "model": _BACKEND,
+            "messages": [{"role": "user", "content": _PROMPT}],
+            "reasoning_effort": "none",
+        }
+        return Reply(body=_completion(identity))
+
+    with wire_server(respond) as wire, gateway.scenario() as scenario:
+        model: Final = scenario.model(model=f"dashscope/{_BACKEND}", api_base=wire.url, api_key=_API_KEY)
+        response: Final = gateway.request(
+            "POST",
+            "/v1/chat/completions",
+            {"model": model, "messages": [{"role": "user", "content": _PROMPT}], "reasoning_effort": "none"},
+        )
+        assert response.status_code == 200, response.text
+        payload: Final = _JSON_OBJECT.validate_json(response.content)
+        assert payload["id"] == identity
+        assert payload["choices"] == [
+            {
+                "finish_reason": "stop",
+                "index": 0,
+                "message": {"role": "assistant", "content": "27", "provider_specific_fields": {"refusal": None}},
+                "provider_specific_fields": {},
+            }
+        ]
+        assert [(request.method, request.target) for request in wire.drain()] == [("POST", "/chat/completions")]