diff --git a/gateway/pyproject.toml b/gateway/pyproject.toml
index a804d42..d7e7e73 100644
--- a/gateway/pyproject.toml
+++ b/gateway/pyproject.toml
@@ -36,3 +36,28 @@ src = ["src"]
 [tool.pytest.ini_options]
 asyncio_mode = "auto"
 testpaths = ["tests"]
+
+[tool.mypy]
+python_version = "3.11"
+
+# The speech extra is deliberately absent from a default setup. `make setup`
+# installs the gateway without it; `make setup-speech` adds faster-whisper and
+# piper-tts, which pull several GB of ML wheels for a backend the deployment
+# does not use — settings.tts_backend defaults to "speaches", a network call to
+# the shared service on 8601. Both imports are lazy, inside the functions that
+# need them, so their absence is a runtime fact rather than a defect.
+#
+# numpy is here for the same reason: nothing depends on it directly, it arrives
+# with faster-whisper.
+#
+# Without these overrides, `make typecheck` fails on a machine that followed the
+# documented setup — the pre-push gate turning red for doing the right thing,
+# which is how a gate stops being read (T-56). The right assertion is "these
+# modules may be absent", not "install several GB so the type checker is happy".
+[[tool.mypy.overrides]]
+module = [
+    "piper", "piper.*",
+    "faster_whisper", "faster_whisper.*",
+    "numpy", "numpy.*",
+]
+ignore_missing_imports = true