diff --git a/doc/source/usage.rst b/doc/source/usage.rst
index cfd5e53..0f8ec5d 100644
--- a/doc/source/usage.rst
+++ b/doc/source/usage.rst
@@ -4,4 +4,4 @@ Usage
 
 To use doc8 in a project::
 
-	import doc8
+    import doc8
diff --git a/test-requirements.txt b/test-requirements.txt
index 64251c7..297c909 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -1,3 +1,4 @@
+doc8
 hacking>=0.9.2,<0.10
 nose
 oslosphinx
diff --git a/tox.ini b/tox.ini
index bf76e77..04ebdab 100644
--- a/tox.ini
+++ b/tox.ini
@@ -21,7 +21,9 @@ downloadcache = ~/cache/pip
 commands = {posargs}
 
 [testenv:docs]
-commands = python setup.py build_sphinx
+commands =
+  doc8 -e .rst doc CONTRIBUTING.rst HACKING.rst README.rst
+  python setup.py build_sphinx
 
 [flake8]
 builtins = _