The singer announced during her show on Wednesday night that she is extending her residency by two years.
"Okay I have some big news tonight," she said in a video posted on Instagram. "Usually I get you guys to help me count to three, but tonight I want you to help me count to two because I'm going to be in Vegas for two more years!"
Spears, 33, began her first-ever residency show at Planet Hollywood Resort and Casino in December 2013. She previously extended her show by three months in May after injuring herself when she took a tumble on stage.