Nature 551, 89–91 (2017); doi:https://doi.org/10.1038/nature24289

In this Letter, there was an inadvertent typo in the fifth line of equation (2). On the right-hand side ‘3He p’ should read ‘4He p’ to give D 3He → 4He p, ΔE = 18.35 MeV. This error has been corrected in the online versions of the paper.