diff --git a/pyproject.toml b/pyproject.toml
index 97433714..5f4975fb 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -71,4 +71,4 @@ __version__ = {version_tuple!r}
 [project.optional-dependencies]
 test = ["testscenarios", "testresources"]
 twisted = ["Twisted", "fixtures"]
-dev = ["ruff==0.9.7"]
+dev = ["ruff==0.9.9"]