diff --git a/requirements.txt b/requirements.txt
index 829c973..bb978d2 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -94,7 +94,7 @@ lmfit==0.9.11
 locket==0.2.0
 lockfile==0.12.2
 louis==3.8.0
-lxml==4.3.2
+lxml==4.6.5
 MarkupSafe==1.1.0
 matplotlib==3.0.2
 mccabe==0.6.1