diff --git a/CONTRIBUTING.rst b/CONTRIBUTING.rst
index ad09fcb26..8ab5bd93a 100644
--- a/CONTRIBUTING.rst
+++ b/CONTRIBUTING.rst
@@ -1,14 +1,14 @@
 If you would like to contribute to the development of OpenStack, you must
 follow the steps in this page:
 
-   http://docs.openstack.org/infra/manual/developers.html
+   https://docs.openstack.org/infra/manual/developers.html
 
 If you already have a good understanding of how the system works and your
 OpenStack accounts are set up, you can skip to the development workflow
 section of this documentation to learn how changes to OpenStack should be
 submitted for review via the Gerrit tool:
 
-   http://docs.openstack.org/infra/manual/developers.html#development-workflow
+   https://docs.openstack.org/infra/manual/developers.html#development-workflow
 
 Pull requests submitted through GitHub will be ignored.
 
diff --git a/HACKING.rst b/HACKING.rst
index d559bfd83..f7a8d3d1a 100644
--- a/HACKING.rst
+++ b/HACKING.rst
@@ -1,4 +1,4 @@
 kayobe Style Commandments
-===============================================
+=========================
 
 Read the OpenStack Style Commandments https://docs.openstack.org/hacking/latest/
diff --git a/doc/requirements.txt b/doc/requirements.txt
index e805c0658..89491a5ef 100644
--- a/doc/requirements.txt
+++ b/doc/requirements.txt
@@ -1,2 +1,7 @@
+# The order of packages is significant, because pip processes them in the order
+# of appearance. Changing the order has an impact on the overall integration
+# process, which may cause wedges in the gate later.
+
 reno!=2.3.1,>=1.8.0 # Apache-2.0
-sphinx>=1.5.1 # 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
diff --git a/test-requirements.txt b/test-requirements.txt
index 23d7f8b3e..3e7dc83b0 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -11,6 +11,7 @@ hacking>=0.12.0,<0.13 # Apache-2.0
 molecule<3 # MIT
 oslotest>=1.10.0 # Apache-2.0
 # NOTE(mgoddard): This is required by tools/sphinx8.
-sphinx>=1.5.1 # 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
 stestr # Apache-2.0
 yamllint # GPLv3