Reflections with Alpha

[ruuterdetuuter]

Hi,

I'm trying to composite a scene with a model and a reflection in the water. I've rendered the two layers, one for the model and one for the water. Then I enabled Layered rendering with an EXR output.
But whenever I want to composite the two, the model has an alpha, but the water doesn't (even though it doesn't fill up the screen). Can anyone tell me why this happens?

[mikefrisk]

You should set the transfer mode to screen for the reflection layer over the water layer.