UIButton with GradientLayer obscures image and darkens gradient

So I managed to get around this by doing a [button bringSubviewToFront:button.imageView] after adding the gradient. Seems that no matter what I do the new layer will add on top of the imageView, so I need to push that to the front afterwards.

Objective-C:

[button bringSubviewToFront:button.imageView] 

Swift 4.1:

button.bringSubview(toFront:button.imageView!)