diff --git a/requirements.3.9.txt b/requirements.3.9.txt
index 89895ce..ca675f3 100644
--- a/requirements.3.9.txt
+++ b/requirements.3.9.txt
@@ -7,7 +7,7 @@ greenlet==1.1.0
 idna==2.10
 joblib==1.0.1
 kiwisolver==1.3.1
-lxml==4.6.3
+lxml==4.9.1
 matplotlib==3.4.2
 numpy==1.20.3
 obspy==1.2.2