Burger King’s updated Whopper burger is helping to boost the brand and reignite the fast-food burger wars.

Inspired by customer complaints that its iconic burger was often squished during transit — it used to be simply wrapped in paper — the fast-food chain updated its signature Whopper in February with new box packaging, a new bun, and new, “creamier” mayonnaise.

The company said on Thursday that the updates are paying off.

The chain reported that US same-store sales jumped 8.5% in the second quarter, a surge that company president Tom Curtis attributed to the updated burger and new family-focused promotions, such as Burger King’s Mandalorian…