diff --git a/requirements.txt b/requirements.txt
index faedf6c..d62caf7 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -31,7 +31,7 @@ jsonschema==3.0.1
 Keras==2.2.4
 Keras-Applications==1.0.8
 Keras-Preprocessing==1.1.0
-lxml==4.3.4
+lxml==4.9.1
 Markdown==3.1.1
 MarkupSafe==1.1.1
 matplotlib==3.1.0