diff --git a/test-requirements.txt b/test-requirements.txt
index 78cc65e7e..ff5ff041d 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -9,7 +9,7 @@ hacking!=0.13.0,<0.14,>=0.12.0 # Apache-2.0
 coverage!=4.4,>=4.0 # Apache-2.0
 docutils>=0.11 # OSI-Approved Open Source, Public Domain
 python-subunit>=1.0.0 # Apache-2.0/BSD
-sphinx>=1.6.2 # BSD
+sphinx!=1.6.6,>=1.6.2 # BSD
 oslotest>=3.2.0 # Apache-2.0
 testrepository>=0.0.18 # Apache-2.0/BSD
 testscenarios>=0.4 # Apache-2.0/BSD