diff --git a/code/requirements.txt b/code/requirements.txt
index ad63fef..183fecd 100644
--- a/code/requirements.txt
+++ b/code/requirements.txt
@@ -72,7 +72,7 @@ lazy-object-proxy==1.3.1
 llvmlite==0.20.0
 locket==0.2.0
 lockfile==0.12.2
-lxml==3.8.0
+lxml==4.9.1
 MarkupSafe==1.0
 matplotlib==2.0.2
 mccabe==0.6.1