Up to now the opening in the containers has been large enough for hedgehogs to get their heads into for a lick of the left-over dessert.
But many became trapped in the containers and died of hunger in untold numbers.
After complaints from animal activists McDonald’s is now making the milkshake carton with a smaller opening so the sugar loving hedgehogs can get into them.
"This is excellent, it is long overdue news," said Fay Vass, chief executive of the British Hedgehog Preservation Society.
"We have been in touch with McDonald's about this problem for over five years and are delighted that they have at last solved the problem."