diff --git a/poetry.lock b/poetry.lock
index 0685ce3a..58d707f3 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -46,7 +46,7 @@ python-versions = "*"
 
 [[package]]
 name = "black"
-version = "21.8b0"
+version = "21.9b0"
 description = "The uncompromising code formatter."
 category = "dev"
 optional = false
@@ -658,7 +658,7 @@ testing = ["pytest (>=4.6)", "pytest-checkdocs (>=2.4)", "pytest-flake8", "pytes
 [metadata]
 lock-version = "1.1"
 python-versions = ">=3.6.2,<4.0"
-content-hash = "dc18ab09ecfe495bc2cdcc1d824a0f0f94af658a8b526797ad2b21a550561504"
+content-hash = "20cd6a0fadb4720e86ce8837c0e93e3cd48ae0e14d27a36b90fdd58cd37f11cf"
 
 [metadata.files]
 astor = [
@@ -681,8 +681,8 @@ backoff-stubs = [
     {file = "backoff-stubs-1.10.0.tar.gz", hash = "sha256:03e995de0a70016c6fe758498e1ca811f1db517c00cbd06e3039c9e4f6ea2566"},
 ]
 black = [
-    {file = "black-21.8b0-py3-none-any.whl", hash = "sha256:2a0f9a8c2b2a60dbcf1ccb058842fb22bdbbcb2f32c6cc02d9578f90b92ce8b7"},
-    {file = "black-21.8b0.tar.gz", hash = "sha256:570608d28aa3af1792b98c4a337dbac6367877b47b12b88ab42095cfc1a627c2"},
+    {file = "black-21.9b0-py3-none-any.whl", hash = "sha256:380f1b5da05e5a1429225676655dddb96f5ae8c75bdf91e53d798871b902a115"},
+    {file = "black-21.9b0.tar.gz", hash = "sha256:7de4cfc7eb6b710de325712d40125689101d21d25283eed7e9998722cf10eb91"},
 ]
 certifi = [
     {file = "certifi-2021.5.30-py2.py3-none-any.whl", hash = "sha256:50b1e4f8446b06f41be7dd6338db18e0990601dce795c2b1686458aa7e8fa7d8"},
diff --git a/pyproject.toml b/pyproject.toml
index 35f45175..fe62659a 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -62,7 +62,7 @@ flake8-isort = "^4.0.0"
 isort = "^5.9.3"
 pep8-naming = "^0.12.1"
 flake8-black = "^0.2.3"
-black = "^21.8b0"
+black = "^21.9b0"
 darglint = "^1.8.0"
 
 # Tests