diff --git a/requirements_test.txt b/requirements_test.txt
index 58e630b..74d39a8 100644
--- a/requirements_test.txt
+++ b/requirements_test.txt
@@ -1,6 +1,6 @@
 pytest
 coverage==5.5
-black==23.3.0
+black==23.9.1
 typing-extensions==4.5.0
 
 # Only for CPython (exclude pypy).