diff --git a/packages/eslint-plugin/src/rules/ban-types.ts b/packages/eslint-plugin/src/rules/ban-types.ts
index 3eb48fb7255..38224b15ce9 100644
--- a/packages/eslint-plugin/src/rules/ban-types.ts
+++ b/packages/eslint-plugin/src/rules/ban-types.ts
@@ -185,8 +185,7 @@ export default util.createRule<Options, MessageIds>({
           customMessage,
         },
         fix: fixWith
-          ? (fixer: TSESLint.RuleFixer): TSESLint.RuleFix =>
-              fixer.replaceText(typeNode, fixWith)
+          ? (fixer): TSESLint.RuleFix => fixer.replaceText(typeNode, fixWith)
           : null,
       });
     }
diff --git a/packages/eslint-plugin/src/rules/consistent-indexed-object-style.ts b/packages/eslint-plugin/src/rules/consistent-indexed-object-style.ts
index 5f2a930db49..bd511d0cd0e 100644
--- a/packages/eslint-plugin/src/rules/consistent-indexed-object-style.ts
+++ b/packages/eslint-plugin/src/rules/consistent-indexed-object-style.ts
@@ -84,7 +84,7 @@ export default createRule<Options, MessageIds>({
         node,
         messageId: 'preferRecord',
         fix: safeFix
-          ? (fixer: TSESLint.RuleFixer): TSESLint.RuleFix => {
+          ? (fixer): TSESLint.RuleFix => {
               const key = sourceCode.getText(keyType.typeAnnotation);
               const value = sourceCode.getText(valueType.typeAnnotation);
               const record = member.readonly
diff --git a/packages/eslint-plugin/src/util/getESLintCoreRule.ts b/packages/eslint-plugin/src/util/getESLintCoreRule.ts
index a26a0676501..5ba9ae36965 100644
--- a/packages/eslint-plugin/src/util/getESLintCoreRule.ts
+++ b/packages/eslint-plugin/src/util/getESLintCoreRule.ts
@@ -42,18 +42,16 @@ type RuleId = keyof RuleMap;
 
 export const getESLintCoreRule: <R extends RuleId>(ruleId: R) => RuleMap[R] =
   isESLintV8
-    ? function <R extends RuleId>(ruleId: R): RuleMap[R] {
-        return ESLintUtils.nullThrows(
+    ? <R extends RuleId>(ruleId: R): RuleMap[R] =>
+        ESLintUtils.nullThrows(
           // eslint-disable-next-line @typescript-eslint/no-unsafe-member-access, @typescript-eslint/no-unsafe-call
           require('eslint/use-at-your-own-risk').builtinRules.get(
             ruleId,
           ) as RuleMap[R],
           `ESLint's core rule '${ruleId}' not found.`,
-        );
-      }
-    : function <R extends RuleId>(ruleId: R): RuleMap[R] {
-        return require(`eslint/lib/rules/${ruleId}`) as RuleMap[R];
-      };
+        )
+    : <R extends RuleId>(ruleId: R): RuleMap[R] =>
+        require(`eslint/lib/rules/${ruleId}`) as RuleMap[R];
 
 export function maybeGetESLintCoreRule<R extends RuleId>(
   ruleId: R,