diff --git a/.github/workflows/lint.yml b/.github/workflows/lint.yml
index 36e8417..899330d 100644
--- a/.github/workflows/lint.yml
+++ b/.github/workflows/lint.yml
@@ -26,8 +26,9 @@ jobs:
           python-version: "3.14"
 
       - name: Install Ruff
-        # Same floor as requirements_dev.txt.
-        run: pip install "ruff>=0.16.3"
+        # Pinned, same as requirements_dev.txt. A new Ruff release can add or
+        # change rules, so bump it on purpose in its own PR.
+        run: pip install "ruff==0.17.0"
 
       - name: Ruff check
         run: ruff check .
diff --git a/custom_components/gree_custom/const.py b/custom_components/gree_custom/const.py
index f4cb6e2..7e3c089 100755
--- a/custom_components/gree_custom/const.py
+++ b/custom_components/gree_custom/const.py
@@ -1,8 +1,6 @@
 """Constants for the Gree integration."""
 
-from homeassistant.components.climate import (
-    HVACMode,  # pyright: ignore[reportPrivateImportUsage]
-)
+from homeassistant.components.climate import HVACMode  # pyright: ignore[reportPrivateImportUsage]
 from homeassistant.const import UnitOfTemperature
 
 from .aiogree.api import (
diff --git a/docs/development.md b/docs/development.md
index 44438ba..44e9d36 100644
--- a/docs/development.md
+++ b/docs/development.md
@@ -184,6 +184,8 @@ Never log an encryption key, cloud password or token in clear text.
 
 `lint.yml` runs `ruff check` and `ruff format --check` on every push and PR.
 
+Ruff is pinned to one exact version, in `lint.yml` and in `requirements_dev.txt`. Keep the two the same. New Ruff releases change rules: 0.16 and 0.17 want opposite forms of the same import, so no code passes both. Bump the pin in its own PR and run `ruff check --fix .` with the new version in that PR.
+
 `validate.yaml` runs three jobs on every push and PR:
 
 - **Hassfest** and **HACS** validation. Neither imports or compiles the Python.
diff --git a/requirements_dev.txt b/requirements_dev.txt
index ef32dd2..823eed6 100755
--- a/requirements_dev.txt
+++ b/requirements_dev.txt
@@ -1,5 +1,5 @@
 # Linting / formatting (same tool HA core uses)
-ruff>=0.16.3
+ruff==0.17.0
 
 # Additional static analysis - HA core's CI also runs these
 pylint>=4.0.7