diff --git a/pyproject.toml b/pyproject.toml
index 3e9c41a..c3ee2f4 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -66,7 +66,7 @@ dev = [
     # can silently drift from what `pre-commit run --all-files` checked.
     # Bump both together (and re-verify) when updating.
     "ruff==0.16.4",
-    "mypy==2.3.0",
+    "mypy==2.3.1",
 
     "types-PyYAML>=6.0.0",
     "bandit==1.9.4",