diff --git a/src/config/index.d.ts b/src/config/index.d.ts
index e5fd90ff..ca7a5b69 100644
--- a/src/config/index.d.ts
+++ b/src/config/index.d.ts
@@ -1,5 +1,6 @@
 import type { Parser, ParserOptions } from '../parser-options';
-import type { Rules } from '../rules';
+import type { Rules as AllRules } from '../rules';
+import type { RuleConfig } from '../rules/rule-config';
 import type { Environments } from './env';
 import type { Extends } from './extends';
 import type { Overrides } from './overrides';
@@ -11,7 +12,10 @@ import type { Settings } from './settings';
  *
  * @see [ESLint Configuration](https://eslint.org/docs/latest/user-guide/configuring/)
  */
-export interface ESLintConfig {
+export interface ESLintConfig<
+  Rules extends Record<string, RuleConfig> = AllRules,
+  Strict extends boolean = false,
+> {
   /**
    * @see [Using Configuration Files](https://eslint.org/docs/latest/user-guide/configuring/configuration-files#using-configuration-files)
    */
@@ -83,7 +87,9 @@ export interface ESLintConfig {
    *
    * @see [Rules](https://eslint.org/docs/latest/user-guide/configuring/rules)
    */
-  rules?: Rules;
+  rules?: Strict extends true
+    ? Partial<Rules>
+    : Partial<Rules & Record<string, RuleConfig>>;
 
   /**
    * Overrides.
diff --git a/src/flat-config/index.d.ts b/src/flat-config/index.d.ts
index 9254effe..2b81d9b5 100644
--- a/src/flat-config/index.d.ts
+++ b/src/flat-config/index.d.ts
@@ -1,5 +1,6 @@
 import type { ESLint, Linter } from 'eslint';
-import type { Rules } from '../rules';
+import type { Rules as AllRules } from '../rules';
+import type { RuleConfig } from '../rules/rule-config';
 import type { LanguageOptions } from './language-options';
 import type { LinterOptions } from './linter-options';
 
@@ -8,7 +9,10 @@ import type { LinterOptions } from './linter-options';
  *
  * @see [Configuration Files (New)](https://eslint.org/docs/latest/user-guide/configuring/configuration-files-new)
  */
-export interface FlatESLintConfigItem {
+export interface FlatESLintConfigItem<
+  Rules extends Record<string, RuleConfig> = AllRules,
+  Strict extends boolean = false,
+> {
   /**
    * An array of glob patterns indicating the files that the configuration object should apply to. If not specified, the configuration object applies to all files.
    *
@@ -54,7 +58,9 @@ export interface FlatESLintConfigItem {
    *
    * @see [Configuring rules](https://eslint.org/docs/latest/user-guide/configuring/configuration-files-new#configuring-rules)
    */
-  rules?: Rules;
+  rules?: Strict extends true
+    ? Partial<Rules>
+    : Partial<Rules & Record<string, RuleConfig>>;
 
   /**
    * An object containing name-value pairs of information that should be available to all rules.
@@ -74,7 +80,10 @@ export interface FlatESLintConfigItem {
  */
 export type PredefinedConfig = 'eslint:recommended' | 'eslint:all';
 
-export type FlatESLintConfig = FlatESLintConfigItem | PredefinedConfig;
+export type FlatESLintConfig<
+  Rules extends Record<string, RuleConfig> = AllRules,
+  Strict extends boolean = false,
+> = FlatESLintConfigItem<Rules, Strict> | PredefinedConfig;
 
 export * from './language-options';
 export * from './linter-options';
diff --git a/src/index.ts b/src/index.ts
index 8c767696..babd56e3 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,5 +1,7 @@
 import type { ESLintConfig } from './config';
 import type { FlatESLintConfig } from './flat-config';
+import type { Rules as AllRules } from './rules';
+import type { RuleConfig } from './rules/rule-config';
 
 /**
  * Define an ESLint config.
@@ -7,7 +9,10 @@ import type { FlatESLintConfig } from './flat-config';
  * @param config ESLint config.
  * @returns ESLint config.
  */
-export function defineConfig(config: ESLintConfig): ESLintConfig {
+export function defineConfig<
+  Rules extends Record<string, RuleConfig> = AllRules,
+  Strict extends boolean = false,
+>(config: ESLintConfig<Rules, Strict>): ESLintConfig {
   return config;
 }
 
@@ -19,7 +24,10 @@ export function defineConfig(config: ESLintConfig): ESLintConfig {
  * @param config an item of Flat ESLint config.
  * @returns an item of Flat ESLint config.
  */
-export function defineFlatConfig(config: FlatESLintConfig): FlatESLintConfig;
+export function defineFlatConfig<
+  Rules extends Record<string, RuleConfig> = AllRules,
+  Strict extends boolean = false,
+>(config: FlatESLintConfig<Rules, Strict>): FlatESLintConfig<Rules, Strict>;
 
 /**
  * Define a flat ESLint config.
@@ -29,9 +37,12 @@ export function defineFlatConfig(config: FlatESLintConfig): FlatESLintConfig;
  * @param config Flat ESLint config.
  * @returns Flat ESLint config.
  */
-export function defineFlatConfig(
-  config: ReadonlyArray<FlatESLintConfig>,
-): FlatESLintConfig[];
+export function defineFlatConfig<
+  Rules extends Record<string, RuleConfig> = AllRules,
+  Strict extends boolean = false,
+>(
+  config: ReadonlyArray<FlatESLintConfig<Rules, Strict>>,
+): Array<FlatESLintConfig<Rules, Strict>>;
 
 export function defineFlatConfig(config: unknown): unknown {
   return config;
diff --git a/src/rules/index.d.ts b/src/rules/index.d.ts
index d1e8e3fc..7109d0ea 100644
--- a/src/rules/index.d.ts
+++ b/src/rules/index.d.ts
@@ -28,29 +28,28 @@ import type { YmlRules } from './yml';
  *
  * @see [Rules](https://eslint.org/docs/user-guide/configuring/rules)
  */
-export type Rules = Partial<
-  DeprecationRules &
-    EslintRules &
-    EslintCommentsRules &
-    GraphQLRules &
-    ImportRules &
-    JSDocRules &
-    JsoncRules &
-    JsxA11yRules &
-    NodeRules &
-    NRules &
-    PromiseRules &
-    ReactHooksRules &
-    ReactRules &
-    SonarJSRules &
-    SpellcheckRules &
-    TestingLibraryRules &
-    TypeScriptRules &
-    UnicornRules &
-    VitestRules &
-    VueRules &
-    VueI18nRules &
-    VuePugRules &
-    YmlRules &
-    Record<string, RuleConfig>
->;
+export interface Rules
+  extends DeprecationRules,
+    EslintRules,
+    EslintCommentsRules,
+    GraphQLRules,
+    ImportRules,
+    JSDocRules,
+    JsoncRules,
+    JsxA11yRules,
+    NodeRules,
+    NRules,
+    PromiseRules,
+    ReactHooksRules,
+    ReactRules,
+    SonarJSRules,
+    SpellcheckRules,
+    TestingLibraryRules,
+    TypeScriptRules,
+    UnicornRules,
+    VitestRules,
+    VueRules,
+    VueI18nRules,
+    VuePugRules,
+    YmlRules,
+    Record<string, RuleConfig> {}