diff --git a/requirements.txt b/requirements.txt
index 6486ae7..c41645b 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,5 +1,5 @@
 cython==0.29.26
-lxml==4.7.1
+lxml==4.9.1
 numpy==1.21.4
 pandas==1.3.5
 patsy==0.5.2