Task timeout error after 900 seconds

Hello,
As a part of my workflow, I created a function that take more than 1 hour to finish. I have noticed the the function under task decorator throw a timeout error after 900 seconds. Based on that I used timeout_seconds paramter = 3600 seconds. However, the task throw the same error after 900 seconds. Can anyone help me to extend the task timeout for more that 15 mins.