.png to .jpg with image_voodoo results in CMYK (not RGB)

Using this code,

def save_as_jpeg(src_path, dest_path)
ImageVoodoo.with_image("#{src_path}") do |img|
img.save “#{dest_path}”

I’m attempting to convert .png format images (RGB color, by definition,
as I understand it) to jpgs. When I do, the resulting jpg has CMYK color
only rather than RGB or TrueColor. It works as expected when converting
from Windows .bmp or other formats which seem to have RGB color.

Is there an option I can specify to ask image_voodoo to preserve RGB
color or am I failing to specify something or specifying something
incorrectly to cause this issue?

I’ve attached a small .png image that exhibits this behavior.

Thanks for your help.