diff --git a/test-requirements.txt b/test-requirements.txt
index bcb2327..be5dfa6 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -7,7 +7,7 @@ mock>=2.0.0 # BSD
 netaddr>=0.7.18 # BSD
 
 # this is required for the docs build jobs
-sphinx>=1.6.2 # BSD
+sphinx!=1.6.6,>=1.6.2 # BSD
 openstackdocstheme>=1.17.0 # Apache-2.0
 
 oslotest>=3.2.0 # Apache-2.0