diff --git a/doc/requirements.txt b/doc/requirements.txt
index 70411996f3..cd98c3b238 100644
--- a/doc/requirements.txt
+++ b/doc/requirements.txt
@@ -4,6 +4,6 @@
 openstackdocstheme>=1.20.0 # Apache-2.0
 osprofiler>=1.4.0 # Apache-2.0
 os-api-ref>=1.4.0 # Apache-2.0
-sphinx!=1.6.6,!=1.6.7,>=1.6.2;python_version>='3.4' # BSD
+sphinx!=1.6.6,!=1.6.7,!=2.1.0,>=1.6.2;python_version>='3.4' # BSD
 sphinx!=1.6.6,!=1.6.7,>=1.6.2,<2.0.0;python_version=='2.7' # BSD
 reno>=2.5.0 # Apache-2.0
diff --git a/test-requirements.txt b/test-requirements.txt
index ff04da1211..d966d21fa1 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -17,7 +17,7 @@ osprofiler>=1.4.0 # Apache-2.0
 os-testr>=1.0.0 # Apache-2.0
 python-subunit>=1.0.0 # Apache-2.0/BSD
 pytz>=2013.6 # MIT
-sphinx!=1.6.6,!=1.6.7,>=1.6.2;python_version>='3.4' # BSD
+sphinx!=1.6.6,!=1.6.7,!=2.1.0,>=1.6.2;python_version>='3.4' # BSD
 sphinx!=1.6.6,!=1.6.7,>=1.6.2,<2.0.0;python_version=='2.7' # BSD
 testrepository>=0.0.18 # Apache-2.0/BSD
 stestr>=2.0.0 # Apache-2.0