The world’s largest public health authority has weighed in with the most authoritative statement yet on the use of Crispr to alter the DNA of human babies. Eight months after a rogue Chinese scientist revealed he had secretly created the world’s first gene-edited children, the World Health Organization is asking countries to put a stop to any experiments that would lead to the births of more gene-edited humans.

On Friday, the WHO’s director-general put out a statement urging “that regulatory authorities in all countries should not allow any further work in this area until its implications have been properly considered.”

While stopping short of the all-out moratorium that many scientists called for in the hours and days after Chinese scientist He Jiankui revealed his controversial work in November, the WHO’s position is a strong rebuke of He’s work. But whether it will prove a powerful deterrent to any who would hope to follow in his footsteps remains to be seen.