Firefox problem: New tabs show up before previously opened tabs on my tab bar?

I had to wipe out my computer and start from scratch, so I had to reinstall Firefox, natch. It’s not that big of a deal, but I got used to having new tabs show up at the end of my tab bar, and now they show up somewhere in the middle. Is there a setting to change this?

You’re probably confused… I’ll try to explain better.
Let’s say I have two tabs open. If I go back into the first tab and open a link, a new tab will open after the first tab, and before the second tab. I want the new tab to open as the third in the list.