OAKVILLE, Ill. – McDonald’s fourth quarter profits last year produced the fast-food chain’s best quarterly results in nearly four years, evidence that the move to an all-day breakfast menu is working.

The Wall Street Journal reports that investors expected all-day breakfast to boost sales, “but not this much.” According to a press release, McDonald’s reports that in the U.S., fourth quarter comparable sales increased 5.7%, benefiting from the October launch of all-day breakfast and, to a lesser extent, unseasonably mild weather. Operating income for the quarter rose 30%, driven by positive comparable sales and a gain from the strategic sale of a unique restaurant property.

McDonald’s CEO Steve Easterbrook said the QSR is “demonstrating that our turnaround plan is key to restarting growth and becoming a modern and progressive burger company. … As we enter 2016, we expect continued positive top-line momentum across all segments."

For more on all-day breakfast in convenience stores, read the January NACS Magazine cover story, “The Most Important Meal All Day.”