10 ILCS 5/24B-14

If any ballot is damaged, defective, or cannot otherwise properly be counted by the automatic Precinct Tabulation Optical Scan Technology tabulating equipment, a true duplicate copy shall be made of the ballot in the presence of witnesses and substituted for the original ballot. Likewise, a duplicate ballot shall not include the invalid votes appearing on the original ballot. All duplicate ballots shall be clearly labeled "Duplicate", shall bear a serial number which shall be registered on the damaged, defective, or otherwise unreadable ballot, and shall be counted in lieu of the damaged, defective, or otherwise unreadable ballot.