diff --git a/requirements.txt b/requirements.txt
index 808c0018..09241dbe 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,4 +1,5 @@
 pbr>=0.6,!=0.7,<1.0
-sphinx!=1.6.6,<1.7.0,>=1.6.2 # BSD
+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
 openstackdocstheme>=1.18.1 # Apache-2.0
 yasfb>=0.5.1