diff --git a/requirements.txt b/requirements.txt
index 49c0175..db0044d 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -24,7 +24,7 @@ Keras==2.2.4
 Keras-Applications==1.0.6
 Keras-Preprocessing==1.0.5
 git+https://github.com/src-d/kmcuda.git#subdirectory=src
-lxml==4.4.2
+lxml==4.9.1
 matplotlib==3.1.1
 mygene==3.0.0
 ndg-httpsclient==0.5.0