diff --git a/test-requirements.txt b/test-requirements.txt
index 86cf39ee3a..1d95790645 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -18,7 +18,7 @@ python-ceilometerclient>=2.5.0 # Apache-2.0
 python-neutronclient>=6.3.0 # Apache-2.0
 python-openstackclient>=3.12.0 # Apache-2.0
 pytz>=2013.6 # MIT
-sphinx>=1.6.2 # BSD
+sphinx!=1.6.6,>=1.6.2 # BSD
 testrepository>=0.0.18 # Apache-2.0/BSD
 testscenarios>=0.4 # Apache-2.0/BSD
 testtools>=2.2.0 # MIT