diff --git a/pyproject.toml b/pyproject.toml
index d29aa8188..4d2c5e299 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -81,7 +81,7 @@ optional-dependencies.dev = [
     "pytest-xdist==3.8.0",
     "pyyaml==6.0.3",
     "requests-mock-flask==2026.2.16",
-    "ruff==0.15.8",
+    "ruff==0.15.9",
     # We add shellcheck-py not only for shell scripts and shell code blocks,
     # but also because having it installed means that ``actionlint-py`` will
     # use it to lint shell commands in GitHub workflow files.