Kids are being urged to go around performing miracles at Hallowe'en rather than playing their more traditional "trick-or-treat" games.
Roman Catholic bishops are saying that kids should not dress up as witches and devils. More acceptable would be costumes such as St George, St Lucy, St Mary Magdalen or St Francis of Assisi.
"All the trick or treat stuff should stop. It's time people knew what Hallowe'en is really about - it's the vigil feast of All Saints' Day," says The Right Rev Harcourt Libation, a spokesman for the International Conference of Really Important Bishops.
"Go out there and perform miracles! Heal the sick, give your clothes to the poor and all that."
However, mothers' groups fear there will be an unintended kids' backlash.
One mum told us: "My little Danny says he wants to go out as St Sebastian. He's seen paintings of him with loads of arrows sticking out of him and he thinks that's pretty neat. You know what boys are."
Also, French authorities have recommended that parents discourage their children from decapitating themselves and walking around like patron saint, St Denis.