# Runtime versions in buildspec file sample for CodeBuild
<a name="sample-runtime-versions"></a>

If you use the Amazon Linux 2 (AL2) standard image version 1.0 or later, or the Ubuntu standard image version 2.0 or later, you can specify one or more runtimes in the `runtime-versions` section of your buildspec file. The following samples show how you can change your project runtime, specify more than one runtime, and specify a runtime that is dependent on another runtime. For information about supported runtimes, see [Docker images provided by CodeBuild](build-env-ref-available.md).

**Note**  
If you use Docker in your build container, your build must run in privileged mode. For more information, see [Run AWS CodeBuild builds manually](run-build.md) and [Create a build project in AWS CodeBuild](create-project.md). 

**Topics**
+ [Update the runtime version in the buildspec file](sample-runtime-update-version.md)
+ [Specify two runtimes](sample-runtime-two-major-version-runtimes.md)