301 redirect when old url and new url are the same at the beginning?

Hi,

I am trying to do a redirect where www.domain.com/directory/Abc_Def will redirect to www.domain.com/directory/Abc_Defghi

I’m running into an infinite loop because the first parts of the url are exactly the same. I tried RewriteRule ^directory/Abc_Def$ /directory/Abc_Defghi [L,R=301] but it didn’t work.

Is there a way to do this?

Thanks!

Looks to me like it should work. I can only suspect that something else in your htaccess is causing the problem.