Stupid Firefox Question

I am sure there is a way to to this just couldnt figure it out.

One of my favorite features of firefox is tabbed browsing. But when I click a link that targets a new window … naturally a new window opens.

Is it possible to configure it to open all new windows in new tabs instead?

I tried playing with the options but couldnt seem to do it.

Am I missing something or do I need to DL an extension to do this?