Cracking raw MD5 hashes with John the Ripper

I just spent at least 15 minutes trying to figure out why every single post on the Internet tells me to place MD5 hash in a file and call John like this

john --format=raw-md5 --wordlist=/usr/share/dict/words md5.txt

and yet, it constantly gives me an error message:

No password hashes loaded (see FAQ)

The content of md5.txt was:

20E11C279CE49BCC51EDC8041B8FAAAA

I even tried prepending dummy user before this hash, like this:

dummyuser: 20E11C279CE49BCC51EDC8041B8FAAAA

but without any luck.

And of course I have extended version of John the Ripper that support raw-md5 format.

It turned out that John doesn't support capital letters in hash value! They have to be written in small letters like this:

20e11c279ce49bcc51edc8041b8fbbb6

after that change, everything worked like a charm. What a stupid error!?