diff --git a/requirements.txt b/requirements.txt
index 8f97a7d..036861e 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -2,4 +2,4 @@ aiohttp>3.1,<3.2
 easyinject==0.3
 marshmallow==2.9.1
 packaging==16.7
-lxml>=3.6.4,<4
+lxml>=3.6.4,<5