Issue when mounting multipath device with label

I got this issue yesterday, trying to mount a multipath device using label:

mount LABEL=ACME /mnt/acme
mount: /dev/sdc5 already mounted or /mnt/acme busy

strace and Google help me to solve this issue:

There's a cache file /etc/blkid/blkid.tab where information about block devices (labels, uuid) are stored. To solve/avoid this issue, just refresh this cache file:

• remove/backup the file
• regenerate it by running blkid command

Doing so, label will be found/used on multipath device first when mounting from label.