Codesandbox: https://codesandbox.io/s/redux-toolkit-rtk-query-forked-6plwhy?file=/src/services/pokemon.ts Somebody had already fixed similar issues, but it was still a problem. Actual behavior: When you add transformResponse to enhanceEndpoints, ResultType doesn't change according to transformResponse ReturnType. Expected behavior: ResultType should be matched with transformReposponse ReturnType. Version: 1.9.7