diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 57a1ccca0..3785ca79b 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -1,6 +1,6 @@
 repos:
   - repo: https://github.com/psf/black
-    rev: 21.8b0
+    rev: 21.9b0
     hooks:
       - id: black
         args:
diff --git a/requirements_tests.txt b/requirements_tests.txt
index 4127753a2..5dd2208d9 100644
--- a/requirements_tests.txt
+++ b/requirements_tests.txt
@@ -1,4 +1,4 @@
-black==21.8b0
+black==21.9b0
 codecov==2.1.12
 coverage==5.5
 flake8-docstrings==1.6.0