Force www except for subdomains

[rEnr3n]

I found this rule here - https://stackoverflow.com/questions/20631015/force-www-in-htaccess-except-all-subdomains

RewriteEngine On
RewriteCond %{HTTP_HOST} ^[0-9a-zA-Z-]+\.[a-zA-Z]{2,}$
RewriteRule ^(.*)$ http://www.%{HTTP_HOST}/$1 [R=301,L]

I get a double slash at the end of the url if i type in an address like server.lan/

So I changed it a bit to look like this:

RewriteEngine On
RewriteCond %{HTTP_HOST} ^[0-9a-zA-Z-]+\.[a-zA-Z]{2,}$
RewriteRule ^(.*)$ https://www.%{HTTP_HOST}%{REQUEST_URI} [R=301,L]

I don't know if it's good though. I made a quick test and it looks ok.