diff --git a/requirements.txt b/requirements.txt
index 98460e3..d9d2f61 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -6,6 +6,7 @@ h11==0.12.0
 httpcore==0.15.0
 httpx==0.23.0
 idna==3.3
+lxml==4.9.1
 rfc3986==1.5.0
 sniffio==1.2.0
 soupsieve==2.3.2.post1