feh won't open DNG files using the ImageMagick convert binary

[ant-222]

According to the man page, feh should try to display DNG files using the ImageMagick covert binary, if a positive value is passed with the --conversion-timeout parameter, but it does not seem to work for me. I have installed ImageMagick and made sure that
convert file.DNG test.jpg
produces correct JPEG output, yet when I run feh as:
feh --conversion-timeout=30 -Fd --force-aliasing --zoom-step=50
it will not convert the .DNG files, immediately showing a built-in thumbnail instead. Please, help.