diff --git a/dev-requirements.txt b/dev-requirements.txt
index 754c7df..54327d3 100644
--- a/dev-requirements.txt
+++ b/dev-requirements.txt
@@ -7,4 +7,4 @@ icalendar==4.1.1
 # test
 pytest==7.4.2
 coverage==6.5.0
-black==23.9.0
+black==23.9.1