diff --git a/test-requirements.txt b/test-requirements.txt
index 93dfa6c7..e013c466 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -3,7 +3,7 @@
 # process, which may cause wedges in the gate later.
 hacking!=0.13.0,<0.14,>=0.12.0 # Apache-2.0
 python-openstackclient>=3.12.0 # Apache-2.0
-sphinx>=1.6.2 # BSD
+sphinx!=1.6.6,>=1.6.2 # BSD
 mock>=2.0.0 # BSD
 nose>=1.3.7 # LGPL
 oslotest>=3.2.0 # Apache-2.0