diff --git a/requirements.txt b/requirements.txt
index b0b43fbd..38619f3a 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -4,7 +4,7 @@
 
 pbr>=1.8 # Apache-2.0
 iso8601>=0.1.11 # MIT
-lxml>=2.3 # BSD
+lxml!=3.7.0,>=2.3 # BSD
 oslo.config!=3.18.0,>=3.14.0 # Apache-2.0
 docutils!=0.13.1,>=0.11 # OSI-Approved Open Source, Public Domain
 sphinx!=1.3b1,<1.4,>=1.2.1 # BSD