Canonical URL issue

Hi, I've the next issue in a SP 2013 blog site:

This blog has anonymous access enable, but I detect canonical URLs are incorrect, i.e. http://www.contoso.com/blog1/Lists/Blogentries/2_.000?ID=2.

I want canonical URLs like http://www.contoso.com/blog1/Lists/Blogentries/post.aspx?ID=2.

How can i get correct canonical URLs?

Thanks in advance!!!

Tomás González. Twitter://@tgmourino