diff --git a/pyproject.toml b/pyproject.toml
index 7fd8b38..cc57b5c 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -67,7 +67,7 @@ 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==2.3.1",
+    "mypy==2.4.0",
 
     "types-PyYAML>=6.0.0",
     "bandit==1.9.4",