diff --git a/requirements.txt b/requirements.txt
index 2ca0e95..cbfeb33 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -7,7 +7,7 @@ iso8601>=0.1.11 # MIT
 lxml!=3.7.0,>=2.3 # BSD
 oslo.config>=3.22.0 # Apache-2.0
 docutils>=0.11 # OSI-Approved Open Source, Public Domain
-sphinx>=1.5.1 # BSD
+sphinx!=1.6.1,>=1.5.1 # BSD
 demjson # GLGPLv3+
 PyYAML>=3.10.0 # MIT
 cliff-tablib>=1.0 # Apache-2.0