diff --git a/doc/source/overview_erasure_code.rst b/doc/source/overview_erasure_code.rst
index 7128c917e5..f5a946c824 100644
--- a/doc/source/overview_erasure_code.rst
+++ b/doc/source/overview_erasure_code.rst
@@ -284,7 +284,7 @@ span beyond a single region, neither performance nor functional validation has
 be been done in such a configuration.
 
 EC Duplication
-^^^^^^^^^^^^^^
+==============
 
 ec_duplication_factor is an option to make duplicate copies of fragments
 of erasure encoded Swift objects. The default value is 1 (not duplicate).
diff --git a/setup.cfg b/setup.cfg
index ea73b2c785..ef655077f0 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -104,6 +104,7 @@ paste.filter_factory =
 all_files = 1
 build-dir = doc/build
 source-dir = doc/source
+warning-is-error = 1
 
 [egg_info]
 tag_build =
diff --git a/test-requirements.txt b/test-requirements.txt
index 04ea66b788..5b944ec544 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -10,7 +10,7 @@ nosexcover # BSD
 nosehtmloutput>=0.0.3 # Apache-2.0
 openstackdocstheme>=1.5.0 # Apache-2.0
 oslosphinx>=4.7.0 # Apache-2.0
-sphinx!=1.3b1,<1.4,>=1.2.1 # BSD
+sphinx>=1.5.1  # BSD
 os-api-ref>=1.0.0 # Apache-2.0
 os-testr>=0.8.0 # Apache-2.0
 mock>=2.0 # BSD