# How to upgrade the Ubuntu version


You can upgrade or downgrade your Ubuntu service to a different major Ubuntu version by setting the [`run.base`](/ubuntu/how-to/build-pipeline#base-1) parameter in your `zerops.yaml`. When you [trigger a new pipeline](/ubuntu/how-to/trigger-pipeline), Zerops will start new runtime container(s) with the required Ubuntu version. If you don't specify the `run.base` attribute in your `zerops.yaml`, Zerops keeps the current Ubuntu version for your runtime.

If you want to build your application with a different major Ubuntu version, change the [`build.base`](/ubuntu/how-to/build-pipeline#base) parameter in your `zerops.yaml`. The `build.base` is the required attribute.