diff --git a/requirements.txt b/requirements.txt
index e4bce00..07fa871 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -68,7 +68,7 @@ jupyter-core==4.3.0
 lazy-object-proxy==1.2.2
 llvmlite==0.18.0
 locket==0.2.0
-lxml==4.6.3
+lxml==4.9.1
 MarkupSafe==0.23
 matplotlib==2.0.2
 mistune==0.8.4