diff --git a/requirements.txt b/requirements.txt
index a7ceaa8..cbca78e 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -14,7 +14,7 @@ ipaddr==2.2.0
 jdcal==1.4.1
 lml==0.1.0
 lockfile==0.12.2
-lxml==4.6.5
+lxml==4.9.1
 msgpack==0.6.2
 numpy==1.21.0
 openpyxl==3.0.7