diff --git a/doc/requirements.txt b/doc/requirements.txt
new file mode 100644
index 00000000..101a16ff
--- /dev/null
+++ b/doc/requirements.txt
@@ -0,0 +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.
+sphinx!=1.6.6,!=1.6.7,>=1.6.2 # BSD
+sphinxcontrib-apidoc>=0.2.0  # BSD
+sphinx_rtd_theme>=0.2.4
+reno>=2.5.0 # Apache-2.0
diff --git a/tox.ini b/tox.ini
index 3fb3b87b..c9dde653 100644
--- a/tox.ini
+++ b/tox.ini
@@ -22,9 +22,10 @@ commands =
     {toxinidir}/tools/run-unit-tests.sh {posargs}
 
 [testenv:docs]
+deps = -r{toxinidir}/doc/requirements.txt
 commands =
     rm -rf doc/build
-    python setup.py build_sphinx
+    sphinx-build -W -b html doc/source doc/build/html
 
 [testenv:genconfig]
 commands =