config: always add www. when generate links
diff --git a/pelicanconf.py b/pelicanconf.py
index d75bf23..33152b0 100644
--- a/pelicanconf.py
+++ b/pelicanconf.py
@@ -20,7 +20,7 @@
 
 # URL path to the root
 _SITEURL = os.getenv('PELICAN_SITEURL')
-SITEURL = 'https://' + _SITEURL
+SITEURL = 'https://www.' + _SITEURL
 
 # URL path to the theme folder
 THEMEURL = SITEURL