diff --git a/docs/README.md b/docs/README.md
new file mode 100644
index 0000000000000000000000000000000000000000..de53f5433000476436fd006471e072eff2751edc
--- /dev/null
+++ b/docs/README.md
@@ -0,0 +1,9 @@
+To build the docs, install the `requirements.txt` in this folder and then run
+`make html`.
+
+That should create a version identical to the one from ReadTheDocs, which can
+be used to preview changes. The files will be stored in `build/html`.
+
+There may be warnings in the build output, but these are legacy and will be
+addressed later.
+
diff --git a/docs/requirements.txt b/docs/requirements.txt
new file mode 100644
index 0000000000000000000000000000000000000000..82133027c9eb6dd3ff20c82704ecf25650e474f5
--- /dev/null
+++ b/docs/requirements.txt
@@ -0,0 +1,2 @@
+sphinx
+sphinx_rtd_theme
diff --git a/docs/source/conf.py b/docs/source/conf.py
index 2ab762b50cdff3113a8d53a9d741169880f98876..4e55fad9b6a4e2a19220a5ce6446fd3ad2794b6e 100644
--- a/docs/source/conf.py
+++ b/docs/source/conf.py
@@ -32,7 +32,8 @@ sys.path.insert(0, os.path.abspath('../..'))
 extensions = [
     'sphinx.ext.autodoc',
     'sphinx.ext.imgmath',
-    'sphinx.ext.autosectionlabel'
+    'sphinx.ext.autosectionlabel',
+    'sphinx_rtd_theme'
 ]
 
 numfig = True
@@ -120,7 +121,7 @@ autodoc_mock_imports = ["portalocker", "argparse", "python-dateutil", "py3dotplu
 
 # The theme to use for HTML and HTML Help pages.  See the documentation for
 # a list of builtin themes.
-html_theme = 'default'
+html_theme = 'sphinx_rtd_theme'
 
 # Theme options are theme-specific and customize the look and feel of a theme
 # further.  For a list of options available for each theme, see the