diff --git a/docs/conf.py b/docs/conf.py
index 5c412c9..9054a75 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -97,7 +97,7 @@ pygments_style = "sphinx"
 
 # The theme to use for HTML and HTML Help pages.  See the documentation for
 # a list of builtin themes.
-html_theme = "sphinx_rtd_theme"
+html_theme = "sphinx_book_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