Lockport's budget surpluses in the past three years have helped raise the city's credit rating.
"The outlook is positive," S&P Global Ratings said after it raised the rating from BBB to BBB+ for general obligation bonds.
Bond ratings affect the city's costs when it borrows money through bonds.
"The city has operated to surpluses in each of the past three years and has benefited from improved monitoring and oversight, supporting our belief that reserves will be maintained at or above current levels going forward," the company said. "The positive outlook reflects our expectation that the City of Lockport is likely to maintain balanced operations over the near term."
The company expects "continued improvement" in the city's financial position.