Car seats are an absolute must for any parent. A car’s safety features are designed for grown adults, and children will not be protected by the standard car seat, especially when they’re very young. Installing the correct children’s car seat in your car will protect your child in the event of an accident significantly more than a standard seatbelt will.

However, many parents make mistakes in purchasing or installing car seats that can have serious consequences. If your seat is installed incorrectly or used incorrectly, your child can still be severely harmed in an accident. The right seat, however, will protect them and minimize any damage. It’s important to read all instructions careful and do research on a car seat before making a purchase. Here are five common car seat mistakes parents can make, and what you should be doing instead.

1. You installed the seat loosely

When you install a car seat in your car, it should be firmly in place and not wiggle more than an inch either way. The straps should be pulled as tight as you can. But a wiggling, loose seat is one of the most common installation problems parents face when installing a car seat. It’s important to check all installation guidelines before putting the car seat in, and you may have to get a locking clip to keep it firmly in place. If it’s wiggling enough that you’re considering measuring, you probably installed it too loosely.

Make sure you use the correct locking mechanism - either the seat belt or the universal anchorage system, but not both, should be used to hold the car seat in place. All cars made after 2002 must accommodate a UAS, but cars made earlier than that may not, so double check your car and your seat before installation to use the right method.

2 You’re using an older seat

It’s vital that you use a new or undamaged car seat when you’re selecting one for your children. It’s not completely unacceptable to use a hand-me-down car seat, but you have to be absolutely sure about its history - if the car seat has ever been installed in a car during an accident, it’s unusable. Even minor fender-benders require replacing the car seat. This is because seats that have been damaged in accidents are weaker and more prone to further damage in another accident. If you don’t know the history of the car seat, don’t use it.

This also means that if you ever get into a car accident, you have to replace the car seat immediately. Don’t wait around until you finish repairing your car after a car accident - pick up a new one that day, or before your child gets back in the car.

3. You didn’t tighten the harness enough

You never want to pull the harnesses so tight that your child is in pain or feels restricted, but parents tend to be overly fearful of tight straps. A well-fitting harness should be able to fit just two fingers underneath, and you should not be able to pinch the strap. Pulling it too loosely won’t protect your child in a car accident, and will cause them to jolt forward more, which risks internal damage and brain damage. A tight strap will minimize their movement during a crash, preventing damage, and will keep them from potentially slipping out.

4. You’re not using an age-appropriate seat

When your kid is under 20 pounds or a year old, they should be in a rear-facing seat. This will provide more safety for their developing head and neck muscles and keep them from flying forward in an accident. But when they reach more than 20 pounds, it’s time to switch to a front-facing seat. Your child should sit in the front-facing seat until they reach about 40 to 65 pounds, depending on the weight limit of your seat, and then ride in a booster seat until their 4’11”. Any earlier, and the car seat strap can cause severe damage to their neck and chest in the event of an accident.

5. The seat is angled incorrectly

Rear-facing seats rest at an incline. It’s important to make sure this incline is accurate - it should be no more than 45 degrees from a vertical position. Measuring the incline is an important factor to consider when considering whether a car seat will fit into your car. Sometimes a seat may fit when folded up, but take up too much space when arranged at an incline - make sure you measure how much space it takes up when it’s angled correctly. Using the right car seat for your child is important, as is making sure it’s installed and used correctly. When you’ve done everything right, the seat will give you peace of mind and protect your child from serious injury in the unfortunate event of a crash. When installed incorrectly, it may not perform to expectations, and you risk causing injury to your child in even minor accidents.