McDonald’s Corp.’s U.S. same-restaurant sales have decelerated over the past year, and Stifel analysts think slower drive-through service and all-day breakfast demand are impacting performance.

McDonald’s MCD, -1.03% reported a 2.3% U.S. same-restaurant sales increase in the fourth quarter, which was in line with the FactSet consensus. From the first through third quarters of 2018, same-store sales growth slowed, rising 2.9%, 2.6% and 2.4%, respectively. Notably, in comparable third and fourth quarters a year earlier, U.S. same-store sales rose 4.1% and 4.5%.

Stifel analysts also noted a U.S. traffic decline of more than 2% during 2018, below what they think franchisees were expecting.

Read:Here are the biggest stock winners on the day the Fed went soft on interest rates

After speaking with franchisees, analysts said they’ve identified four reasons why U.S. same-store sales have been hampered: slower drive-through service owing to a more complex menu, including fresh beef burgers; a customer shift away from the early part of the day because of all-day breakfast, and a resulting impact on service at other meals; greater dependence on national rather than local value messaging; and a lower-than-expected boost from upgrades that include self-serve kiosks.

McDonald’s Chief Executive Stephen Easterbrook acknowledged on the earnings call that the fast-food giant could get a traffic boost from a “renewed focus on the drive-through operation and in just making sure that [it] can really still meet the demand that we’re seeing,” according to a FactSet transcript.

And he discussed the negative all-day breakfast effect on morning business, which analysts say is impacting sales cadence throughout the day.

“So to be very specific, we continue to lose traffic at a greater level than we want at breakfast,” Easterbrook said.

Despite the issues, Stifel analysts are bullish about McDonald’s going into 2019.

See: Starbucks could get dragged into politics by a Howard Schultz run for president

Related: Howard Schultz criticized for - among other things - not knowing how much Cheerios cost

“All else being equal, we would consider becoming more constructive of McDonald’s shares at a better entry point as we believe progress is being made to increase guest counts,” a Stifel note says.

Analysts there rate McDonald’s stock hold with a $174 price target.

KeyBanc Capital Markets still sees opportunity in breakfast.

“Looking ahead, we hope to see improved messaging, new innovation and localized value as drivers of improvement during the morning daypart,” analysts led by Eric Gonzalez wrote.

KeyBanc analysts think delivery, which is now available from more than 19,000 restaurants around the world, according to Easterbrook, “franchise system alignment,” and a “leaner corporate structure” will lower volatility in same-restaurant sales in the long-term.

How check-out free retail could save U.S. consumers 118 hours per year

KeyBanc rates McDonald’s shares overweight with a $195 price target.

SunTrust Robinson Humphrey analysts think delivery and mobile ordering will be the keys to same-restaurant sales acceleration in 2019.

“An additional boost could come from increased drive-through throughput, which is a focus in 2019 after five years of increasing service times,” analysts wrote.

“The performance of international markets (third consecutive year of traffic growth despite a roughly flat market), driven by past digital investments, is an indication that the U.S. momentum will be sustainable long-term.”

SunTrust rates McDonald’s shares buy with a $200 price target.