diff --git a/test-requirements.txt b/test-requirements.txt
index b8d041d..4c90a32 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -6,7 +6,7 @@ hacking<0.11,>=0.10.0
 
 coverage!=4.4,>=4.0 # Apache-2.0
 python-subunit>=1.0.0 # Apache-2.0/BSD
-sphinx>=1.6.2 # BSD
+sphinx!=1.6.6,>=1.6.2 # BSD
 openstackdocstheme>=1.17.0 # Apache-2.0
 testrepository>=0.0.18 # Apache-2.0/BSD
 testtools>=2.2.0 # MIT