diff --git a/requirements.txt b/requirements.txt
index 78ab336..6e7a669 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -53,7 +53,7 @@ pyyaml==6.0.2
 # wcwidth==0.2.13
 
 # https://pypi.org/project/sphinxcontrib-email/
-lxml==5.3.1
+lxml==6.1.0
 sphinxcontrib-email==0.3.6
 
 # https://pypi.org/project/yasfb/