diff --git a/setup.cfg b/setup.cfg
index bfccbe5..d49d390 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -16,5 +16,8 @@ all_files = 1
 build-dir = doc/build
 source-dir = doc/source
 
+[pbr]
+warnerrors = True
+
 [wheel]
 universal = 1
diff --git a/tox.ini b/tox.ini
index e34b4dc..aacefbe 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,9 +1,9 @@
 [tox]
 minversion = 1.6
+envlist = docs
 skipsdist = True
 
 [testenv]
-sitepackages = True
 usedevelop = True
 setenv = VIRTUAL_ENV={envdir}
 install_command = pip install -U {opts} {packages}
@@ -12,5 +12,5 @@ deps = -r{toxinidir}/requirements.txt
 [testenv:venv]
 commands = {posargs}
 
-[testenv:build_specs]
+[testenv:docs]
 commands = python setup.py build_sphinx