To be frank, fans of a popular Chicago-style hot dog chain may not relish this news.

Portillo’s plans to close a “mid-to-high single-digit number” of underperforming restaurants outside the Chicago area, mostly by the end of the year, CEO Brett Patterson announced Thursday.

The Chicago-based fast-casual chain, known for its hot dogs and Italian beef sandwiches, has 109 locations nationwide. It said it looked at each restaurant’s sales, operating costs and expected future performance before deciding which ones to close. The company has not yet announced the affected locations.

“This will improve portfolio quality, strengthen returns on invested capital and reflect our commitment to disciplined growth,” Patterson said.

The move comes as Portillo’s looks to get back on track after struggling to find the same success in markets outside Chicago.

Portillo’s plans to put more focus on its existing restaurants and take a more careful approach to opening new locations, particularly in unfamiliar markets. Patterson said the chain has struggled to connect with customers in some newer markets because of how its restaurants were branded.

“We did a little damage to ourselves with how we branded the restaurants [outside Chicago],” Patterson said during a third-quarter financial results conference call, Nation’s Restaurant News reports. “In some of them, we have the name Portillo’s. We took off what we do, what we serve. And, for new market penetration, if they don’t know what you do, it’s kind of hard for people to figure out.”

To improve the customer experience, Portillo’s plans to invest more in employee training, technology and restaurant equipment. The chain is also working on a new marketing strategy and a simpler customer loyalty program.

Despite the planned closures, Portillo’s is still growing. The company has opened seven restaurants this year, all in Texas, and expects to open another location in Chicago before the end of the year.

Portillo’s reported a 1.4 percent increase in sales at established restaurants during the third quarter, even as customer visits dipped slightly, according to the company. Overall revenue rose 7 percent to $194.1 million, while net income reached $4.8 million.

The company also raised its earnings forecast for the year, suggesting that it expects business to improve.