The last transition from glacial to interglacial conditions represents the largest natural climate change in Earth’s recent history1. As temperatures rose, the thick ice sheets covering high latitudes receded, spilling water into the oceans. The associated sea-level increase began about 20,000 yr ago and culminated about 7,000 yr ago, in a total rise of 120 m. Sea level did not, however, increase steadily after the Last Glacial Maximum. Between about 14,000 and 15,000 yr ago, sea level as reconstructed at Barbados rose suddenly by about 20 m in just a few centuries, an event known as Meltwater Pulse 1A. More resolved dates from Tahiti suggest the event occurred at the transition from a period of Northern Hemisphere cooling known as Heinrich Stadial 1 to the subsequent period of warming, known as the Bølling–Allerød warm interval. The source of the meltwater, however, remains contentious. Writing in Nature Geoscience, Mackintosh et al. report combining estimates of the timing and magnitude of ice-sheet retreat in the Mac. Robertson Land sector of East Antarctica with ice-sheet modelling to constrain the contribution of East Antarctica to sea-level rise, suggesting little to no input to the jump in sea level 14,000–15,000 yr ago.