diff --git a/README.md b/README.md
index 1b3db50..b25634a 100644
--- a/README.md
+++ b/README.md
@@ -174,16 +174,16 @@ You can still force this behavior by using `emitError` **or** `emitWarning` opti
 #### `emitError`
 
 - Type: `Boolean`
-- Default: `false`
+- Default: `true`
 
-Will always return errors, if set to `true`.
+The errors found will always be emitted, to disable set to `false`.
 
 #### `emitWarning`
 
 - Type: `Boolean`
-- Default: `false`
+- Default: `true`
 
-Will always return warnings, if set to `true`.
+The warnings found will always be emitted, to disable set to `false`.
 
 #### `failOnError`
 
diff --git a/declarations/ESLintError.d.ts b/declarations/ESLintError.d.ts
index 2d533bf..a38d07e 100644
--- a/declarations/ESLintError.d.ts
+++ b/declarations/ESLintError.d.ts
@@ -1,8 +1,7 @@
-export default class ESLintError {
+export default class ESLintError extends WebpackError {
   /**
    * @param {string=} messages
    */
   constructor(messages?: string | undefined);
-  name: string;
-  stack: string;
 }
+import { WebpackError } from 'webpack';
diff --git a/declarations/cjs.d.ts b/declarations/cjs.d.ts
index 428d31f..e9ca127 100644
--- a/declarations/cjs.d.ts
+++ b/declarations/cjs.d.ts
@@ -1,2 +1,2 @@
-declare const _exports: typeof import('.').ESLintWebpackPlugin;
+declare const _exports: typeof import('.').default;
 export = _exports;
diff --git a/declarations/index.d.ts b/declarations/index.d.ts
index 7ae2022..b7bf9b6 100644
--- a/declarations/index.d.ts
+++ b/declarations/index.d.ts
@@ -1,4 +1,8 @@
-export class ESLintWebpackPlugin {
+export default ESLintWebpackPlugin;
+export type Compiler = import('webpack').Compiler;
+export type Options = import('./options').PluginOptions &
+  import('eslint').ESLint.Options;
+declare class ESLintWebpackPlugin {
   /**
    * @param {Options} options
    */
@@ -21,7 +25,3 @@ export class ESLintWebpackPlugin {
    */
   getContext(compiler: Compiler): string;
 }
-export default ESLintWebpackPlugin;
-export type Compiler = import('webpack').Compiler;
-export type Options = import('./options').PluginOptions &
-  import('eslint').ESLint.Options;
diff --git a/src/getESLint.js b/src/getESLint.js
index fe27f1b..92a6b66 100644
--- a/src/getESLint.js
+++ b/src/getESLint.js
@@ -1,4 +1,4 @@
-import os from 'os';
+import { cpus } from 'os';
 
 import JestWorker from 'jest-worker';
 
@@ -96,7 +96,7 @@ export default function getESLint(key, { threads, ...options }) {
   const max =
     typeof threads !== 'number'
       ? threads
-        ? os.cpus().length - 1
+        ? cpus().length - 1
         : 1
       : /* istanbul ignore next */
         threads;
diff --git a/src/index.js b/src/index.js
index e68bbcc..4a8c232 100644
--- a/src/index.js
+++ b/src/index.js
@@ -1,7 +1,8 @@
 import { isAbsolute, join } from 'path';
 
+// @ts-ignore
 import arrify from 'arrify';
-import micromatch from 'micromatch';
+import { isMatch } from 'micromatch';
 
 import { getOptions } from './options';
 import linter from './linter';
@@ -13,7 +14,7 @@ import { parseFiles, parseFoldersToGlobs } from './utils';
 const ESLINT_PLUGIN = 'ESLintWebpackPlugin';
 let counter = 0;
 
-export class ESLintWebpackPlugin {
+class ESLintWebpackPlugin {
   /**
    * @param {Options} options
    */
@@ -99,11 +100,7 @@ export class ESLintWebpackPlugin {
         if (module.resource) {
           const [file] = module.resource.split('?');
 
-          if (
-            file &&
-            micromatch.isMatch(file, wanted) &&
-            !micromatch.isMatch(file, exclude)
-          ) {
+          if (file && isMatch(file, wanted) && !isMatch(file, exclude)) {
             // Queue file for linting.
             lint(file);
           }
diff --git a/src/linter.js b/src/linter.js
index f8d7967..efb5884 100644
--- a/src/linter.js
+++ b/src/linter.js
@@ -106,16 +106,18 @@ export default function linter(key, options, compilation) {
      */
     async function generateReportAsset({ compiler }) {
       const { outputReport } = options;
-      // @ts-ignore
+      /**
+       * @param {string} name
+       * @param {string | Buffer} content
+       */
       const save = (name, content) =>
-        new Promise((finish, bail) => {
+        /** @type {Promise<void>} */ (new Promise((finish, bail) => {
           const { mkdir, writeFile } = compiler.outputFileSystem;
           // ensure directory exists
           // @ts-ignore - the types for `outputFileSystem` are missing the 3 arg overload
           mkdir(dirname(name), { recursive: true }, (err) => {
             /* istanbul ignore if */
             if (err) bail(err);
-            // @ts-ignore
             else
               writeFile(name, content, (err2) => {
                 /* istanbul ignore if */
@@ -123,7 +125,7 @@ export default function linter(key, options, compilation) {
                 else finish();
               });
           });
-        });
+        }));
 
       if (!outputReport || !outputReport.filePath) {
         return;
@@ -179,14 +181,9 @@ function parseResults(options, results) {
 
   results.forEach((file) => {
     if (fileHasErrors(file)) {
-      const messages = file.messages.filter((message) => {
-        if (options.emitError === undefined) {
-          return true;
-        } else if (options.emitError) {
-          return message.severity === 2;
-        }
-        return false;
-      });
+      const messages = file.messages.filter(
+        (message) => options.emitError && message.severity === 2
+      );
 
       if (messages.length > 0) {
         errors.push({
@@ -197,14 +194,9 @@ function parseResults(options, results) {
     }
 
     if (fileHasWarnings(file)) {
-      const messages = file.messages.filter((message) => {
-        if (options.emitWarning === undefined) {
-          return true;
-        } else if (options.emitWarning) {
-          return message.severity === 1;
-        }
-        return false;
-      });
+      const messages = file.messages.filter(
+        (message) => options.emitWarning && message.severity === 1
+      );
 
       if (messages.length > 0) {
         warnings.push({
diff --git a/src/options.js b/src/options.js
index b235ad6..2bc449e 100644
--- a/src/options.js
+++ b/src/options.js
@@ -1,5 +1,6 @@
 import { validate } from 'schema-utils';
 
+// @ts-ignore
 import schema from './options.json';
 
 /** @typedef {import("eslint").ESLint.Options} ESLintOptions */
@@ -47,6 +48,8 @@ import schema from './options.json';
 export function getOptions(pluginOptions) {
   const options = {
     extensions: 'js',
+    emitError: true,
+    emitWarning: true,
     failOnError: true,
     ...pluginOptions,
     ...(pluginOptions.quiet ? { emitError: true, emitWarning: false } : {}),
@@ -78,6 +81,5 @@ export function getESLintOptions(loaderOptions) {
     delete eslintOptions[option];
   }
 
-  // @ts-ignore
   return eslintOptions;
 }
diff --git a/src/options.json b/src/options.json
index 68f77fc..b006321 100644
--- a/src/options.json
+++ b/src/options.json
@@ -7,11 +7,11 @@
       "type": "string"
     },
     "emitError": {
-      "description": "Will always return errors, if set to `true`.",
+      "description": "The errors found will always be emitted, to disable set to `false`.",
       "type": "boolean"
     },
     "emitWarning": {
-      "description": "Will always return warnings, if set to `true`.",
+      "description": "The warnings found will always be emitted, to disable set to `false`.",
       "type": "boolean"
     },
     "eslintPath": {
diff --git a/src/utils.js b/src/utils.js
index 03a35ae..2fe85d2 100644
--- a/src/utils.js
+++ b/src/utils.js
@@ -1,5 +1,6 @@
 import { statSync } from 'fs';
 
+// @ts-ignore
 import arrify from 'arrify';
 
 const UNESCAPED_GLOB_SYMBOLS_RE = /(\\?)([()*?[\]{|}]|^!|[!+@](?=\())/g;
@@ -11,7 +12,7 @@ const UNESCAPED_GLOB_SYMBOLS_RE = /(\\?)([()*?[\]{|}]|^!|[!+@](?=\())/g;
  */
 export function parseFiles(files, context) {
   return arrify(files).map(
-    (file) =>
+    (/** @type {string} */ file) =>
       `${replaceBackslashes(context).replace(
         UNESCAPED_GLOB_SYMBOLS_RE,
         '\\$2'
@@ -36,12 +37,12 @@ export function parseFoldersToGlobs(patterns, extensions = []) {
   const extensionsList = arrify(extensions);
   const [prefix, postfix] = extensionsList.length > 1 ? ['{', '}'] : ['', ''];
   const extensionsGlob = extensionsList
-    .map((extension) => extension.replace(/^\./u, ''))
+    .map((/** @type {string} */ extension) => extension.replace(/^\./u, ''))
     .join(',');
 
   return arrify(patterns)
-    .map((pattern) => replaceBackslashes(pattern))
-    .map((pattern) => {
+    .map((/** @type {string} */ pattern) => replaceBackslashes(pattern))
+    .map((/** @type {string} */ pattern) => {
       try {
         // The patterns are absolute because they are prepended with the context.
         const stats = statSync(pattern);
diff --git a/tsconfig.json b/tsconfig.json
index 4c6551b..30a40b7 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -6,7 +6,6 @@
     "checkJs": true,
     "strict": true,
     "types": ["node"],
-    "esModuleInterop": true,
     "resolveJsonModule": true
   },
   "include": ["./src/**/*"]