permalinks for pages (not for posts)

my problem is that, in my permalinks options page i have set custome permalink struqture like this

/%postname%.html

and it works for posts, like this myblog.com/post-name.html but for pages this structure doesn’t work. the page links are still like this myblog.com/page-name (without .html in the end)
and i want to have the same permalinks for pages, as i have for posts