Adding /blog in front of single posts (only)

I would like to add /blog in front of the url for a single post:

e.g.

• website.com/blog/news-article - single article
• website.com/blog - blog archive (showing a list of all blogs etc.)

Ive tried adding /blog/%postname% as the permalink structure, however it adds it in front of everything, including some custom post types:

e.g.

• website.com/blog/shops/single-shop-page

How do I go about adding it in front of posts but nothing else?

Thanks in Advance!

M