A big policy change is coming to Six Flags Great Adventure during one of the busiest times of the year.

Children ages 15 and under will not be allowed inside without a chaperone during the evening hours. One chaperone can supervise up to 10 children. That chaperone must be at least 21 years of age or older and must present a valid photo ID with date of birth.

The new policy starts at 5 p.m. Saturday evening.

Six Flags Great Adventure posted the change on its Facebook page over the weekend.

According to the new policy, the chaperone must accompany the group of kids walking in and must be reachable by phone once inside the park and cannot leave.

Guests ages 16 or older may also be asked to show a photo ID with date of birth or risk being refused entry. Anyone ages 15 or under without a chaperone while the policy is in effect may be kicked out of the park.

The policy is in effect for all-season pass and ticket holders and could be enforced earlier in the day at the discretion of Six Flags management.