30 indexes ... error: cannot export over 31 indexes

So I’m trying to use xtrabackup to create an export of one table. This table is reasonably sized and has 30 indexes.

When I go to prepare for export, I get the error that > 31 indexes is not supported. I only have 30, am I missing something?

140922 12:08:42 Percona XtraDB (http://www.percona.com) 5.1.73-14.6 started; log sequence number 1102864377356
xtrabackup: export option is specified.
xtrabackup: export metadata of table ‘va_tom/call_history’ to file ./va_tom/call_history.exp (30 indexes)
xtrabackup: name=PRIMARY, id.low=2417, page=3
… (another 29 indexes)
xtrabackup: error: sorry, cannot export over 31 indexes for now.