diff --git a/requirements.txt b/requirements.txt
index 2b2bc7f..68cfcb3 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -3,7 +3,7 @@ chardet==3.0.4
 et-xmlfile==1.0.1
 idna==2.8
 jdcal==1.4.1
-lxml==4.4.1
+lxml==4.9.1
 multitasking==0.0.9
 numpy==1.17.4
 openpyxl==3.0.0