Stephanie Pratt — castmember on MTV’s The Hills and sister of reality villain Spencer Pratt — was arrested early Sunday morning on suspicion of driving under the influence, PEOPLE has confirmed.

According to LAPD officials, Stephanie was arrested at 3:45 a.m. in Hollywood and charged with a misdemeanor. “It was your basic DUI. Our traffic officers driving down the street spotted her and pulled her over,” Sgt. Sal Ogaz told PEOPLE.com. “She was cooperative and there were no issues with her arrest.”

On Saturday night, the star Tweeted that she was heading for fellow Hills star Holly Montag’s birthday party at Los Angeles hotspot Empire.

Her tweet read, “It’s my sissy @hollymontags b-day party! Just finished dinner and going to Empire but I’m pretty tired, a.k.a. yes, I am the party pooper.”

Stephanie and Holly left the club at 2 AM and headed for Beso, where they stayed another hour before calling it a night.