Brantley Gilbert and Jana Kramer

One Tree Hill alum Jana Kramer and country star Brantley Gilbert have called off their engagement, People reports.

Celebs who are out and proud

A source close to the couple says the duo split because of their busy careers, insisting that there was no "foul play" involved.

Gilbert, 28 and Kramer, 29, had been dating for a year when the former popped the question at the Nashville's Ryman Auditorium Theater in January. Kramer was previously married to actor Johnathon Schaech for one month.