Crash tests that measure how safe your child is in the back seat of your car aren't up to scratch, say safety researchers at Euro NCAP.
But that's set to change, with the introduction of larger dummies representing older kids.
At present only two child dummy sizes - 18 months and 3 years - are used when a car is crash-tested. However, Euro NCAP says that as children between these ages are almost always strapped into child seats locked into ISOFIX anchor points, the seatbelts in the rear are not being tested.
NCAP technical manager Richard Schram says: "At the moment, the way we assess child safety is using car seats, which in nine out of 10 cases don't use any of the rear seatbelt restraint systems.
"So we don't think that the consumer is best served, as not everyone has these seats."
The new regime will ditch the 18-month-old and 3-year-old dummies and replace them with dummies for those aged 6 and 10.
As these older, larger children use booster seats, the car's seatbelts, which they rely on, will be scrutinised.
Schram says: "We have seen really advanced seatbelt systems in the front and this technology is not being transferred to the rear.
"We need a more advanced seatbelt with pre-tensioners so it will be more forgiving and allow you the children to move forward a little in a crash.
"By using older child dummies we will start to encourage the car makers to do that."
Manufacturers whose rear seatbelts fall short will achieve lower scores in the child protection section of the Euro NCAP crash test when the new dummies are introduced, which will mean a lower overall star rating for the car.
The new dummies won't be introduced into the Euro NCAP crash tests until 2015.
However, as early as next year, a new child seat rating could be included in the tests.
Euro NCAP will also be using scores from crash tests by Europe's largest automobile club, ADAC, to check the safety of a wide range of child seats - not just the expensive manufacturer-recommended models.
"ADAC is already crash-testing child seats," Schram says, "so we will use the ones with the best scores, covering all the groups, and install them to check the seat's fitment in the car, and ensure there are no problems."