diff --git a/docs/contributing.rst b/docs/contributing.rst
index a151f7a0d..971e6ca05 100644
--- a/docs/contributing.rst
+++ b/docs/contributing.rst
@@ -94,9 +94,11 @@ To release a new version of the theme, core team will take the following steps:
    (with regards to alpha release and development versions). The version
    increment should reflect these releases and any potentially breaking changes.
 #. Update the changelog (``docs/changelog.rst``) with the version information.
-#. Run ``npm run build`` to rebuild all the theme assets.
-#. Run ``python setup.py update_translations`` to compile new translation files and update Transifex
-#. Commit that change.
+#. Run ``python setup.py update_translations`` to compile new translation files
+   and update Transifex.
+#. Run ``python setup.py build`` to rebuild all the theme assets and the Python
+   package.
+#. Commit these changes.
 #. Tag the release in git: ``git tag $NEW_VERSION``.
 #. Push the tag to GitHub: ``git push --tags origin``.
 #. Upload the package to PyPI:
diff --git a/setup.py b/setup.py
index c937eacd1..dd6a1494b 100644
--- a/setup.py
+++ b/setup.py
@@ -5,12 +5,43 @@
 
 """
 
+import os
 import subprocess
 import distutils.cmd
+import setuptools.command.build_py
 from io import open
 from setuptools import setup
 
 
+class WebpackBuildCommand(setuptools.command.build_py.build_py):
+
+    """Prefix Python build with Webpack asset build"""
+
+    def run(self):
+        if not 'CI' in os.environ:
+            subprocess.run(['node_modules/.bin/webpack', '--config', 'webpack.prod.js'], check=True)
+        setuptools.command.build_py.build_py.run(self)
+
+
+class WebpackDevelopCommand(distutils.cmd.Command):
+
+    description = "Run Webpack dev server"
+
+    user_options = []
+
+    def initialize_options(self):
+        pass
+
+    def finalize_options(self):
+        pass
+
+    def run(self):
+        subprocess.run(
+            ["node_modules/.bin/webpack-dev-server", "--open", "--config", "webpack.dev.js"],
+            check=True
+        )
+
+
 class UpdateTranslationsCommand(distutils.cmd.Command):
 
     description = "Run all localization commands"
@@ -47,8 +78,8 @@ def finalize_options(self):
         pass
 
     def run(self):
-        subprocess.run(['tx', 'push', '--source'])
-        subprocess.run(['tx', 'pull'])
+        subprocess.run(['tx', 'push', '--source'], check=True)
+        subprocess.run(['tx', 'pull'], check=True)
 
 
 setup(
@@ -63,6 +94,8 @@ def run(self):
     cmdclass={
         'update_translations': UpdateTranslationsCommand,
         'transifex': TransifexCommand,
+        'build_py': WebpackBuildCommand,
+        'watch': WebpackDevelopCommand,
     },
     zip_safe=False,
     packages=['sphinx_rtd_theme'],