diff --git a/requirements.txt b/requirements.txt
index f4533f5..20c46c3 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -67,7 +67,7 @@ ipython==4.0.0
 ipython-genutils==0.1.0
 isodate==0.5.4
 kombu==3.0.35
-lxml==3.6.1
+lxml==4.6.3
 MapProxy==1.9.0
 mccabe==0.3.1
 MultipartPostHandler==0.1.0