diff --git a/requirements.txt b/requirements.txt
index 5f865e02..6da8be7a 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,3 +1,4 @@
+lxml >= 4.3.0
 pyVmomi >= 6.7
 suds ; python_version < '3'
 suds-jurko ; python_version >= '3.0'