diff --git a/test-requirements.txt b/test-requirements.txt
index 1494e3e..5488850 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -3,7 +3,7 @@
 # process, which may cause wedges in the gate later.
 
 Pillow>=2.4.0 # PIL License
-sphinx>=1.5.1 # BSD
+sphinx!=1.6.1,>=1.5.1 # BSD
 mock>=2.0 # BSD
 coverage!=4.4,>=4.0 # Apache-2.0
 testrepository>=0.0.18 # Apache-2.0/BSD