diff --git a/test-requirements.txt b/test-requirements.txt
index 3078f8b..63dc2f2 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -6,7 +6,7 @@ hacking>=0.12.0,<0.13 # Apache-2.0
 
 coverage>=4.0,!=4.4 # Apache-2.0
 sphinx!=1.6.6,!=1.6.7,>=1.6.2,<2.0.0;python_version=='2.7'  # BSD
-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
 oslotest>=1.10.0 # Apache-2.0
 testrepository>=0.0.18  # Apache-2.0/BSD
 testtools>=1.4.0 # MIT