Damn Small Linux: aes module not working

Question

I try to get losetup with aes encryption working on a Damn Small Linux 4.11 rc2, but without success:

# modprobe aes
$ dd if=/dev/random ibs=512 count=256 of=crypt.img
# losetup -e aes /dev/loop0 crypt.img
# mkfs.ext3 /dev/loop0
# mkdir /mnt/crypted
# mount /dev/loop0 /mnt/crypted

The aes module appears in /proc/crypto and lsmod, but is not used by the loop module. It looks like losetup is incomplete, it accepts anything for the -e option. I am looking for any hint...