diff --git a/requirements.txt b/requirements.txt
index f5db3b8..3e06eed 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -5,7 +5,7 @@ black==22.6.0
 online-judge-tools==11.5.1
 
 # notebook
-ipykernel==6.15.1
+ipykernel==6.21.1
 
 # lib
 numpy==1.18.2