diff --git a/CHANGELOG.md b/CHANGELOG.md
index cf3c69364ccd..8596c878de23 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -13,12 +13,12 @@
 - `[jest-matcher-utils]` Fix diff highlight of symbol-keyed object. ([#9499](https://github.com/facebook/jest/pull/9499))
 - `[jest-resolve]` Fix module identity preservation with symlinks and browser field resolution ([#9511](https://github.com/facebook/jest/pull/9511))
 - `[jest-resolve]` Do not confuse directories with files ([#8912](https://github.com/facebook/jest/pull/8912))
+- `[jest-resolve]` Fix `moduleNameMapper` does not work with core modules name ([#9563](https://github.com/facebook/jest/pull/9563))
 - `[jest-runtime]` Reset `isolateModules` if it fails ([#9541](https://github.com/facebook/jest/pull/9541))
 - `[jest-snapshot]` Downgrade semver to v6 to support node 8 ([#9451](https://github.com/facebook/jest/pull/9451))
 - `[jest-snapshot]` Properly indent new snapshots in the presences of existing ones ([#9523](https://github.com/facebook/jest/pull/9523))
 - `[jest-transform]` Correct sourcemap behavior for transformed and instrumented code ([#9460](https://github.com/facebook/jest/pull/9460))
 - `[pretty-format]` Export `OldPlugin` type ([#9491](https://github.com/facebook/jest/pull/9491))
-- `[jest-resolve]` Fix `moduleNameMapper` does not work with core modules name ([#9563](https://github.com/facebook/jest/pull/9563))
 
 ### Chore & Maintenance
 
diff --git a/packages/jest-resolve/src/index.ts b/packages/jest-resolve/src/index.ts
index 003e93d3576f..ec6c3ab48657 100644
--- a/packages/jest-resolve/src/index.ts
+++ b/packages/jest-resolve/src/index.ts
@@ -218,7 +218,7 @@ class Resolver {
     );
   }
 
-  private _isAliasModule(moduleName: string) {
+  private _isAliasModule(moduleName: string): boolean {
     const moduleNameMapper = this._options.moduleNameMapper;
     if (!moduleNameMapper) {
       return false;