ShadowCastingMode gives error

Hello,

I am trying to disable casting shadows of an object using ShadowCastingMode inside an editor window. I tried it and got an error, so I then tried the code at runtime and got the same error:

Unknown identifier: ‘ShadowCastingMode’.

Using the code:

function Start () {
	var renderer = gameObject.GetComponent(MeshRenderer) as MeshRenderer;
	renderer.shadowCastingMode = ShadowCastingMode.Off;
}

ShadowCastingMode is an enumerator so this code should work, or have I missed something?

renderer.shadowCastingMode = UnityEngine.Rendering.ShadowCastingMode.On ;
or
renderer.shadowCastingMode = UnityEngine.Rendering.ShadowCastingMode.Off ;