diff --git a/dev-requirements.txt b/dev-requirements.txt
index 10e950b..4f68ef6 100644
--- a/dev-requirements.txt
+++ b/dev-requirements.txt
@@ -2,7 +2,7 @@
 requests==2.32.3
 beautifulsoup4==4.12.3
 tqdm==4.66.5
-icalendar==4.1.1
+icalendar==6.0.1
 
 # test
 pytest==7.4.4