diff --git a/requirements.txt b/requirements.txt
index 7d1aeba..d5f1b51 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -67,7 +67,7 @@ jupyter-core==4.2.1
 lazy-object-proxy==1.2.2
 llvmlite==0.16.0
 locket==0.2.0
-lxml==3.7.2
+lxml==4.9.1
 MarkupSafe==0.23
 matplotlib==2.0.0
 mistune==0.7.3