diff --git a/requirements.txt b/requirements.txt
index d97fa02..a93634f 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,5 +1,5 @@
 aiohappyeyeballs==2.6.1
-aiohttp==3.13.5
+aiohttp==3.14.0
 aiosignal==1.4.0
 annotated-types==0.7.0
 anyio==4.13.0
diff --git a/test/conftest.py b/test/conftest.py
index c5142da..f1f3979 100644
--- a/test/conftest.py
+++ b/test/conftest.py
@@ -24,6 +24,51 @@ import aiohttp
 import httpx
 import pytest
 
+# ── Patch aioresponses for aiohttp 3.14.0 compatibility ──────────────────────
+# aiohttp 3.14.0 added a required `stream_writer` parameter to
+# `ClientResponse.__init__()`. The released `aioresponses==0.7.8` does not pass
+# this argument, causing:
+#   TypeError: ClientResponse.__init__() missing 1 required keyword-only argument:
+#   'stream_writer'
+#
+# We monkey-patch `ClientResponse.__init__` to accept `stream_writer` with a
+# default value when called from aioresponses (i.e. when `writer` is None).
+
+try:
+    from aiohttp.client_reqrep import ClientResponse
+
+    _ClientResponse__init__ = ClientResponse.__init__
+
+    def _patched_client_response_init(
+        self,
+        method,
+        url,
+        *,
+        writer,
+        continue100,
+        timer,
+        request_info,
+        traces,
+        loop,
+        session,
+        stream_writer=None,  # type: ignore[assignment]
+    ):
+        # If stream_writer was not provided (aioresponses 0.7.8), create a mock.
+        # When writer is None (mocked response), stream_writer.output_size is read.
+        if writer is None and stream_writer is None:
+            mock_writer = MagicMock()
+            mock_writer.output_size = 0
+            stream_writer = mock_writer
+        return _ClientResponse__init__(
+            self, method, url, writer=writer, continue100=continue100,
+            timer=timer, request_info=request_info, traces=traces,
+            loop=loop, session=session, stream_writer=stream_writer,
+        )
+
+    ClientResponse.__init__ = _patched_client_response_init  # type: ignore[assignment]
+except Exception:
+    pass  # If patching fails, tests will fail with a clear TypeError instead
+
 _TEST_DIR = Path(__file__).parent
 # Must be set before importing router so module-level Config.from_yaml + Config field
 # defaults pick these up. db_path is intentionally absent from config_test.yaml so the