diff --git a/prepro/requirements.txt b/prepro/requirements.txt
old mode 100755
new mode 100644
index adc1d46..0ec7d7a
--- a/prepro/requirements.txt
+++ b/prepro/requirements.txt
@@ -40,7 +40,7 @@ launchpadlib==1.10.6
 lazr.restfulclient==0.13.5
 lazr.uri==1.0.3
 louis==3.5.0
-lxml==4.2.1
+lxml==4.6.3
 macaroonbakery==1.1.3
 Mako==1.0.7
 Markdown==3.0.1