diff --git a/test-requirements.txt b/test-requirements.txt
index 212ef58..2716d92 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -5,6 +5,6 @@
 hacking!=0.13.0,<0.14,>=0.12.0 # Apache-2.0
 
 # this is required for the docs build jobs
-sphinx>=1.5.1 # BSD
+sphinx!=1.6.1,>=1.5.1 # BSD
 
 reno>=1.8.0 # Apache-2.0