Friends who bought a second-hand sofa from a charity shop found $41,000 (£24,000) stuffed inside the cushion covers.
Calli Guasti told local news station KTVU, "Our neighbours thought we won the lottery or something 'cause we were just screaming."
But that was not the end of the story - realising the envelope that contained the hidden treasure had a name on it, the pair successfully contacted the rightful owner.
The haul belonged to a retired woman who had stashed her life savings in the sofa, before her unwitting family donated it to the Salvation Army.
The woman, who has not been named, gave the roommates a $1,000 (£600) for their honesty.