Smoke was seen coming from the roof of Oriental Express Restaurant on Cameron Road in North Austin.
The damage from the fire is minimal.
The Austin Fire Department says the fire could have been a lot worse, and possibly spread to other stores in the strip mall, if it weren't for the passerby who saw smoke coming from the roof and called 911.
"Crews got here to see fire on top of the roof. It made access to both the restaurant and the roof and discovered the fire was burning in the roof assembly...quickly got it knocked down within 5 minutes," said Battalion Chief Palmer Buck.
An electrical issue in the roof is believed to be what caused the fire.
There is only minor smoke damage to the restaurant.
Buck says the restaurant expects to open today.