diff --git a/reference/pti/golang.rst b/reference/pti/golang.rst
index 0d592febb..de341ef16 100644
--- a/reference/pti/golang.rst
+++ b/reference/pti/golang.rst
@@ -211,7 +211,7 @@ that should:
 * Either install any needed distro dependencies from the ``doc`` tag in
   ``bindep.txt`` or emit an error if they are not installed.
 * Install Python dependencies for Sphinx from ``doc/requirements.txt``.
-* Execute ``sphinx-build -b html doc/source doc/build``
+* Execute ``sphinx-build -W -b html doc/source doc/build``
 
 Source
 ~~~~~~
diff --git a/reference/pti/python.rst b/reference/pti/python.rst
index 47fb6e038..0ea75f29f 100644
--- a/reference/pti/python.rst
+++ b/reference/pti/python.rst
@@ -28,7 +28,7 @@ tree:
  - tox -ecover
  - python setup.py sdist
  - python setup.py bdist_wheel
- - sphinx-build -b html doc/source doc/build
+ - sphinx-build -W -b html doc/source doc/build
 
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