diff --git a/docs/conf.py b/docs/conf.py
index ed5c1f3..239b545 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -15,7 +15,7 @@
 
 import sys
 import os
-import shlex
+# import shlex
 
 # If extensions (or modules to document with autodoc) are in another directory,
 # add these directories to sys.path here. If the directory is relative to the
@@ -25,7 +25,7 @@ sys.path.insert(0, os.path.join(os.path.abspath('.'), 'ext'))
 # -- General configuration ------------------------------------------------
 
 # If your documentation needs a minimal Sphinx version, state it here.
-#needs_sphinx = '1.0'
+# needs_sphinx = '1.0'
 
 # Add any Sphinx extension module names here, as strings. They can be
 # extensions coming with Sphinx (named 'sphinx.ext.*') or your custom
@@ -112,6 +112,15 @@ pygments_style = 'sphinx'
 todo_include_todos = False
 
 
+# on_rtd is whether we are on readthedocs.org
+on_rtd = os.environ.get('READTHEDOCS', None) == 'True'
+
+if not on_rtd:  # only import and set the theme if we're building docs locally
+    import sphinx_rtd_theme
+    html_theme = 'sphinx_rtd_theme'
+    html_theme_path = [sphinx_rtd_theme.get_html_theme_path()]
+
+# otherwise, readthedocs.org uses their theme by default, so no need to specify it
 # -- Options for HTML output ----------------------------------------------
 
 # The theme to use for HTML and HTML Help pages.  See the documentation for