New Post: Overlay with partial alpha

I'm trying to do a simple overlay of an image with partial opacity on top of another image which is fully opaque. The problem is, the resulting image, instead of being fully opaque has partial opacity where the alpha was in the overlay. Almost like the alpha channel is being multiplied with the image, instead of being just an overlay. Any ideas?
version 7.0.0.0007 x64

MagickImage face = new MagickImage(myByte);
MagickImage overlay = new MagickImage("bubble_overlay.png");
MagickImage circleMask = new MagickImage("circle_mask.png");

face.Resize(183, 183);
face.Mask = circleMask;
MagickImage outfile = new MagickImage(MagickColor.Transparent, 265, 265);
outfile.Composite(face, Gravity.Center, CompositeOperator.SrcOver);
outfile.Composite(overlay, Gravity.Center, CompositeOperator.SrcOver);

outfile.Write("output.png");