A Twin Peaks-area man found himself the victim of a nonconsensual trade Wednesday, when he discovered his bike had been swapped out by a presumed thief.

Police say that the crime went down at some point between 5 p.m. Tuesday and noon on Wednesday, at a home on the first block of Mountain Spring Avenue.

According to the San Francisco Police Department, the 59-year-old male victim noticed that his garage door was open. When he checked inside to see if anything was missing, he "located old bicycle in garage that did not belong to him."

It was only then,police say, that the man realized that his bicycle, which had been stored in the since-breached garage, was missing.

The man didn't see the suspect, so the police don't have any information on who might be responsible and say that no arrests have been made. As always, the SFPD suggests that you check out and follow their garage safety tips to avoid a similar fate.