If I put a 1600 speed stick in a 1300 slot, it'll work but at 1300, right?

I got this mb online, and said it supported up to 1600, but apparently I have to overclock it for it to go that high. Now, it has overclocking built in, so I suppose it's safe to do that, but I want to be sure.

Yes, I already got the 1600 ram sticks.