Namespace Gamecenter not found on Unity 2017.2

Recently upgraded to Unity 2017.2.0f3 and am trying to build my game which worked fine on older versions of unity. I've checked the references here: https://docs.unity3d.com/ScriptReference/SocialPlatforms.GameCenter.GameCenterPlatform.html And it seems like this is all still working as expected but for some reason its not being found when a build is made. Error I get is the following:

The type or namespace name GameCenter' does not exist in the namespace UnityEngine.SocialPlatforms'. Are you missing an assembly reference?

Any idea what I'm missing here? Thank you!