diff --git a/Doc/conf.py b/Doc/conf.py
index 20086a9c18a..28dd80f8590 100644
--- a/Doc/conf.py
+++ b/Doc/conf.py
@@ -44,7 +44,7 @@ exclude_patterns = ['venv/*']
 # -----------------------
 
 # Use our custom theme.
-html_theme = 'classic'
+html_theme = 'pydoctheme'
 html_theme_path = ['tools']
 html_theme_options = {'collapsiblesidebar': True}