Carnival Cruise Lines changed the itinerary Thursday for two of its ships ahead of Tropical Storm Isaac.

Carnival Valor, an eight-day cruise that left Miami on August 18, was expected to return to Miami on Saturday after a stop in Nassau, Bahamas.

However, Carnival announced Valor would skip its stop in Nassau and return to Miami on Sunday instead.

Carnival Liberty, which also left Miami on August 18, will return to Miami on Sunday instead of Saturday. Liberty is also skipping a stop in Nassau.