A worker incorrectly put the notes in the $10 bill slot

Customers at an ATM in the US state of Texas got a pleasant surprise on Sunday: free money.

A Bank of America machine in Houston was giving out $100 bills instead of $10s.

A worker had incorrectly loaded $100 bills in the $10 bill slot.

After word of the glitch got out on social media, the ATM was shut down and temporarily guarded by police.

But officials have said customers can keep the extra cash they got as a result of the error.