diff --git a/index.js b/index.js
index d1b2c120aa..8426993e5b 100644
--- a/index.js
+++ b/index.js
@@ -11,98 +11,108 @@ function filterRules(rules, predicate) {
 
 /**
  * @param {object} rules - rules object mapping rule name to rule module
- * @returns {Record<string, 2>}
+ * @returns {Record<string, 2 | 'error'>}
  */
 function configureAsError(rules) {
   return fromEntries(Object.keys(rules).map((key) => [`react/${key}`, 2]));
 }
 
+/** @type {Partial<typeof allRules>} */
 const activeRules = filterRules(allRules, (rule) => !rule.meta.deprecated);
+/** @type {Record<keyof typeof activeRules, 2 | 'error'>} */
 const activeRulesConfig = configureAsError(activeRules);
 
+/** @type {Partial<typeof allRules>} */
 const deprecatedRules = filterRules(allRules, (rule) => rule.meta.deprecated);
 
+/** @type {['react']} */
 // for legacy config system
 const plugins = [
   'react',
 ];
 
-const plugin = {
-  deprecatedRules,
-  rules: allRules,
-  configs: {
-    recommended: {
-      plugins,
-      parserOptions: {
-        ecmaFeatures: {
-          jsx: true,
-        },
-      },
-      rules: {
-        'react/display-name': 2,
-        'react/jsx-key': 2,
-        'react/jsx-no-comment-textnodes': 2,
-        'react/jsx-no-duplicate-props': 2,
-        'react/jsx-no-target-blank': 2,
-        'react/jsx-no-undef': 2,
-        'react/jsx-uses-react': 2,
-        'react/jsx-uses-vars': 2,
-        'react/no-children-prop': 2,
-        'react/no-danger-with-children': 2,
-        'react/no-deprecated': 2,
-        'react/no-direct-mutation-state': 2,
-        'react/no-find-dom-node': 2,
-        'react/no-is-mounted': 2,
-        'react/no-render-return-value': 2,
-        'react/no-string-refs': 2,
-        'react/no-unescaped-entities': 2,
-        'react/no-unknown-property': 2,
-        'react/no-unsafe': 0,
-        'react/prop-types': 2,
-        'react/react-in-jsx-scope': 2,
-        'react/require-render-return': 2,
+const configs = {
+  recommended: {
+    plugins,
+    parserOptions: {
+      ecmaFeatures: {
+        jsx: true,
       },
     },
-    all: {
-      plugins,
-      parserOptions: {
-        ecmaFeatures: {
-          jsx: true,
-        },
-      },
-      rules: activeRulesConfig,
+    rules: {
+      'react/display-name': 2,
+      'react/jsx-key': 2,
+      'react/jsx-no-comment-textnodes': 2,
+      'react/jsx-no-duplicate-props': 2,
+      'react/jsx-no-target-blank': 2,
+      'react/jsx-no-undef': 2,
+      'react/jsx-uses-react': 2,
+      'react/jsx-uses-vars': 2,
+      'react/no-children-prop': 2,
+      'react/no-danger-with-children': 2,
+      'react/no-deprecated': 2,
+      'react/no-direct-mutation-state': 2,
+      'react/no-find-dom-node': 2,
+      'react/no-is-mounted': 2,
+      'react/no-render-return-value': 2,
+      'react/no-string-refs': 2,
+      'react/no-unescaped-entities': 2,
+      'react/no-unknown-property': 2,
+      'react/no-unsafe': 0,
+      'react/prop-types': 2,
+      'react/react-in-jsx-scope': 2,
+      'react/require-render-return': 2,
     },
-    'jsx-runtime': {
-      plugins,
-      parserOptions: {
-        ecmaFeatures: {
-          jsx: true,
-        },
-        jsxPragma: null, // for @typescript/eslint-parser
+  },
+  all: {
+    plugins,
+    parserOptions: {
+      ecmaFeatures: {
+        jsx: true,
       },
-      rules: {
-        'react/react-in-jsx-scope': 0,
-        'react/jsx-uses-react': 0,
+    },
+    rules: activeRulesConfig,
+  },
+  'jsx-runtime': {
+    plugins,
+    parserOptions: {
+      ecmaFeatures: {
+        jsx: true,
       },
+      jsxPragma: null, // for @typescript/eslint-parser
+    },
+    rules: {
+      'react/react-in-jsx-scope': 0,
+      'react/jsx-uses-react': 0,
     },
   },
 };
 
-plugin.configs.flat = {
+/** @typedef {{ plugins: { react: typeof plugin }, rules: import('eslint').Linter.RulesRecord, languageOptions: { parserOptions: import('eslint').Linter.ParserOptions } }} ReactFlatConfig */
+
+/** @type {{ deprecatedRules: typeof deprecatedRules, rules: typeof allRules, configs: typeof configs & { flat?: Record<string, ReactFlatConfig> }}} */
+const plugin = {
+  deprecatedRules,
+  rules: allRules,
+  configs,
+};
+
+/** @type {Record<string, ReactFlatConfig>} */
+configs.flat = {
   recommended: {
     plugins: { react: plugin },
-    rules: plugin.configs.recommended.rules,
-    languageOptions: { parserOptions: plugin.configs.recommended.parserOptions },
+    rules: configs.recommended.rules,
+    languageOptions: { parserOptions: configs.recommended.parserOptions },
   },
   all: {
     plugins: { react: plugin },
-    rules: plugin.configs.all.rules,
-    languageOptions: { parserOptions: plugin.configs.all.parserOptions },
+    rules: configs.all.rules,
+    languageOptions: { parserOptions: configs.all.parserOptions },
   },
   'jsx-runtime': {
     plugins: { react: plugin },
-    rules: plugin.configs['jsx-runtime'].rules,
-    languageOptions: { parserOptions: plugin.configs['jsx-runtime'].parserOptions },
+    rules: configs['jsx-runtime'].rules,
+    languageOptions: { parserOptions: configs['jsx-runtime'].parserOptions },
   },
 };