diff --git a/pyproject.toml b/pyproject.toml
index 866170cd..b0e90cad 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -41,7 +41,7 @@ dev-docstrings = [
   "darglint == 1.8.1",
   "tomli == 2.0.1",      # Needed by pydocstyle to read pyproject.toml
 ]
-dev-formatting = ["black == 23.7.0", "isort == 5.12.0"]
+dev-formatting = ["black == 23.9.1", "isort == 5.12.0"]
 dev-mkdocs = [
   "mike == 1.1.2",
   "mkdocs-gen-files == 0.5.0",