[fetchmail] sslfingerprint not parsed correctly?

I am using stock Red Hat 7.2 fetchmail:

% fetchmail --version
This is fetchmail release 5.9.0+IMAP-GSS+NTLM+SSL+INET6+NLS

I added 'ssl' to my options in fetchmailrc and was presently
surprised to see everything work.

I saw messages such as thing in my syslog:

mail.attbi.com key fingerprint: 1D:23:01:4A:5E:76:E2:F4:D2:41:F0:84:A6:A3:CF:A5

So I figured I'd add the fingerprint to the rc for a little additional
security. It doesn't seem to parse correctly though. When I use:

  ssl sslproto tls1
  sslfingerprint 1D:23:01:4A:5E:76:E2:F4:D2:41:F0:84:A6:A3:CF:A5

I get:

parse error at 23

Which is the second hex byte. If I remove the colons, it parses, but
then:

mail.attbi.com fingerprints do not match!

Man page seems to say I'm doing it right. Why won't it parse?

Thanks much,
Jeremy