diff --git a/requirements.txt b/requirements.txt
index 5a6282b..8a9d9e7 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -8,7 +8,7 @@ exchangelib==1.9.6
 future==0.16.0
 html2text==2016.9.19
 idna==2.6
-lxml==4.2.5
+lxml==4.9.1
 ntlm-auth==1.0.2
 ordereddict==1.1
 packaging==16.8