diff --git a/install/notebook/requirements.txt b/install/notebook/requirements.txt
index 7725c889..dd4bccf0 100644
--- a/install/notebook/requirements.txt
+++ b/install/notebook/requirements.txt
@@ -29,7 +29,7 @@ umalqurra==0.2                 # arabic calendars (?? why use ??)
 networkx==1.11
 pandas==0.18.0
 six==1.10.0
-lxml==3.5.0
+lxml==4.9.1
 requests-futures==0.9.7
 bs4==0.0.1
 requests==2.10.0