diff --git a/pyproject.toml b/pyproject.toml
index 39f324e..1d87223 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -13,7 +13,7 @@ dependencies = [
 [project.optional-dependencies]
 dev = [
     "pytest>=6.0,<7",
-    "black==20.8b1",
+    "black==21.12b0",
     "flake8>=3.8,<4"
 ]
 
@@ -27,7 +27,7 @@ python_requires = ">=3.8"
 [tool.pdm.dev-dependencies]
 test = [
     "pytest>=6.0,<7",
-    "black==20.8b1",
+    "black==21.12b0",
     "flake8>=3.8,<4"
 ]