diff --git a/requirements-dev.txt b/requirements-dev.txt
index dbc11d9..9ebd0ab 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt
@@ -1,5 +1,5 @@
 # Developer / CI tooling — NOT installed into the runtime image.
 # Install locally with:  pip install -r requirements-dev.txt
 # (pytest itself ships in requirements.txt so the image can run the suite.)
-ruff>=0.9,<0.10
+ruff>=0.15.21,<0.16
 pre-commit>=4.0