diff --git a/requirements.txt b/requirements.txt
index 6e98172..4b1a837 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -87,7 +87,7 @@ lightgbm==2.1.0
 llvmlite==0.18.0
 lml==0.0.2
 locket==0.2.0
-lxml==3.7.3
+lxml==4.9.1
 MarkupSafe==1.0
 matplotlib==2.0.2
 mistune==0.7.4