diff --git a/test-requirements.txt b/test-requirements.txt
index 5863226e1..35262b01f 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -24,7 +24,7 @@ PyMySQL>=0.7.6 # MIT License
 psycopg2>=2.6.2 # LGPL/ZPL
 
 # doc build requirements
-sphinx!=1.6.6,>=1.6.2 # BSD
+sphinx!=1.6.6,<1.7.0,>=1.6.2 # BSD
 sphinxcontrib-httpdomain>=1.3.0 # BSD
 reno>=2.5.0 # Apache-2.0
 openstackdocstheme>=1.18.1 # Apache-2.0