Costco has introduced a small but seismic update to its famous $1.50 hot dog combo, marking the first significant change to the meal’s composition in more than 40 years.

Costco now allows customers to substitute a 16.9-ounce bottle of Kirkland Signature water for the traditional 20-ounce fountain soda. While the pairing has evolved, the price — which has remained a flat $1.50 since the 1980s — remains firmly intact.