diff --git a/.eslintrc.json b/.eslintrc.json
index 7e7ac3a2..b42aaf5c 100644
--- a/.eslintrc.json
+++ b/.eslintrc.json
@@ -10,8 +10,9 @@
   "plugins": [
     "compat",
     "deprecation",
-    "@typescript-eslint",
-    "simple-import-sort"
+    "prefer-arrow-functions",
+    "simple-import-sort",
+    "@typescript-eslint"
   ],
   "extends": [
     "eslint:recommended",
@@ -20,13 +21,20 @@
     "plugin:@typescript-eslint/stylistic-type-checked"
   ],
   "rules": {
+    "arrow-body-style": ["error", "as-needed"],
     "camelcase": "error",
+    "no-warning-comments": "warn",
+    "strict": ["error", "never"],
     "compat/compat": "warn",
     "deprecation/deprecation": "warn",
-    "no-warning-comments": "warn",
+    "prefer-arrow-functions/prefer-arrow-functions": [
+      "error",
+      {
+        "allowNamedFunctions": true
+      }
+    ],
     "simple-import-sort/imports": "error",
     "simple-import-sort/exports": "error",
-    "strict": ["error", "never"],
     "@typescript-eslint/array-type": ["error", {"default": "generic"}],
     "@typescript-eslint/consistent-type-exports": "error",
     "@typescript-eslint/consistent-type-imports": "error",
diff --git a/gulpfile.js b/gulpfile.js
index 69cac70a..1a7b4ecc 100644
--- a/gulpfile.js
+++ b/gulpfile.js
@@ -10,55 +10,55 @@ const shell = require('gulp-shell');
 const terser = require('gulp-terser');
 const ts = require('gulp-typescript');
 
-gulp.task('build:css:admin', function () {
-	return gulp
+gulp.task('build:css:admin', () =>
+	gulp
 		.src(['src/css/admin/*.css'])
 		.pipe(cleanCSS())
 		.pipe(rename({ suffix: '.min' }))
-		.pipe(gulp.dest('dist/admin/css/'));
-});
+		.pipe(gulp.dest('dist/admin/css/'))
+);
 
-gulp.task('build:css:frontend', function () {
-	return gulp
+gulp.task('build:css:frontend', () =>
+	gulp
 		.src(['src/css/frontend/*.css'])
 		.pipe(cleanCSS())
 		.pipe(rename({ suffix: '.min' }))
-		.pipe(gulp.dest('dist/frontend/css/'));
-});
+		.pipe(gulp.dest('dist/frontend/css/'))
+);
 
-gulp.task('build:css:modules:Register:admin', function () {
-	return gulp
+gulp.task('build:css:modules:Register:admin', () =>
+	gulp
 		.src(['src/css/modules/Register/admin/*.css'])
 		.pipe(cleanCSS())
 		.pipe(rename({ suffix: '.min' }))
-		.pipe(gulp.dest('dist/modules/Register/admin/css/'));
-});
+		.pipe(gulp.dest('dist/modules/Register/admin/css/'))
+);
 
 gulp.task(
 	'build:css:modules:Register',
 	gulp.parallel('build:css:modules:Register:admin')
 );
 
-gulp.task('build:css:modules:Shortcodes:admin', function () {
-	return gulp
+gulp.task('build:css:modules:Shortcodes:admin', () =>
+	gulp
 		.src(['src/css/modules/Shortcodes/admin/*.css'])
 		.pipe(cleanCSS())
 		.pipe(rename({ suffix: '.min' }))
-		.pipe(gulp.dest('dist/modules/Shortcodes/admin/css/'));
-});
+		.pipe(gulp.dest('dist/modules/Shortcodes/admin/css/'))
+);
 
 gulp.task(
 	'build:css:modules:Shortcodes',
 	gulp.parallel('build:css:modules:Shortcodes:admin')
 );
 
-gulp.task('build:css:modules:Visibility:admin', function () {
-	return gulp
+gulp.task('build:css:modules:Visibility:admin', () =>
+	gulp
 		.src(['src/css/modules/Visibility/admin/*.css'])
 		.pipe(cleanCSS())
 		.pipe(rename({ suffix: '.min' }))
-		.pipe(gulp.dest('dist/modules/Visibility/admin/css/'));
-});
+		.pipe(gulp.dest('dist/modules/Visibility/admin/css/'))
+);
 
 gulp.task(
 	'build:css:modules:Visibility',
@@ -74,13 +74,13 @@ gulp.task(
 	)
 );
 
-gulp.task('build:css:rules:admin', function () {
-	return gulp
+gulp.task('build:css:rules:admin', () =>
+	gulp
 		.src(['src/css/rules/admin/*.css'])
 		.pipe(cleanCSS())
 		.pipe(rename({ suffix: '.min' }))
-		.pipe(gulp.dest('dist/rules/admin/css/'));
-});
+		.pipe(gulp.dest('dist/rules/admin/css/'))
+);
 
 gulp.task('build:css:rules', gulp.parallel('build:css:rules:admin'));
 
@@ -106,8 +106,8 @@ gulp.task(
 			'composer dump-autoload --no-dev' +
 				(process.env.NODE_ENV === 'production' ? ' -o' : '')
 		),
-		function () {
-			return merge(
+		() =>
+			merge(
 				gulp.src([
 					'vendor/composer/autoload_classmap.php',
 					//'vendor/composer/autoload_files.php',
@@ -134,8 +134,7 @@ gulp.task(
 							"'Skautis_Integration\\\\Vendor\\\\$1\\\\' => \n"
 						)
 					)
-			).pipe(gulp.dest('dist/vendor/composer/'));
-		},
+			).pipe(gulp.dest('dist/vendor/composer/')),
 		shell.task('composer dump-autoload')
 	)
 );
@@ -145,36 +144,36 @@ gulp.task(
 	gulp.series('build:deps:composer:scoper', 'build:deps:composer:autoloader')
 );
 
-gulp.task('build:deps:npm:datatables.net:files', function () {
-	return gulp
+gulp.task('build:deps:npm:datatables.net:files', () =>
+	gulp
 		.src([
 			'node_modules/datatables.net-dt/images/sort_asc.png',
 			'node_modules/datatables.net-dt/images/sort_desc.png',
 			'node_modules/datatables.net-plugins/i18n/cs.json',
 		])
-		.pipe(gulp.dest('dist/bundled/datatables-files'));
-});
+		.pipe(gulp.dest('dist/bundled/datatables-files'))
+);
 
 gulp.task(
 	'build:deps:npm:datatables.net',
-	gulp.parallel('build:deps:npm:datatables.net:files', function () {
-		return gulp
+	gulp.parallel('build:deps:npm:datatables.net:files', () =>
+		gulp
 			.src([
 				'node_modules/datatables.net-dt/css/jquery.dataTables.min.css',
 				'node_modules/datatables.net/js/jquery.dataTables.min.js',
 			])
-			.pipe(gulp.dest('dist/bundled/'));
-	})
+			.pipe(gulp.dest('dist/bundled/'))
+	)
 );
 
-gulp.task('build:deps:npm:font-awesome:css', function () {
-	return gulp
+gulp.task('build:deps:npm:font-awesome:css', () =>
+	gulp
 		.src('node_modules/font-awesome/css/font-awesome.min.css')
-		.pipe(gulp.dest('dist/bundled/font-awesome/css'));
-});
+		.pipe(gulp.dest('dist/bundled/font-awesome/css'))
+);
 
-gulp.task('build:deps:npm:font-awesome:fonts', function () {
-	return gulp
+gulp.task('build:deps:npm:font-awesome:fonts', () =>
+	gulp
 		.src([
 			'node_modules/font-awesome/fonts/fontawesome-webfont.eot',
 			'node_modules/font-awesome/fonts/fontawesome-webfont.woff2',
@@ -182,8 +181,8 @@ gulp.task('build:deps:npm:font-awesome:fonts', function () {
 			'node_modules/font-awesome/fonts/fontawesome-webfont.ttf',
 			'node_modules/font-awesome/fonts/fontawesome-webfont.svg',
 		])
-		.pipe(gulp.dest('dist/bundled/font-awesome/fonts'));
-});
+		.pipe(gulp.dest('dist/bundled/font-awesome/fonts'))
+);
 
 gulp.task(
 	'build:deps:npm:font-awesome',
@@ -193,35 +192,35 @@ gulp.task(
 	)
 );
 
-gulp.task('build:deps:npm:interactjs', function () {
-	return gulp
+gulp.task('build:deps:npm:interactjs', () =>
+	gulp
 		.src('node_modules/interactjs/dist/interact.min.js')
-		.pipe(gulp.dest('dist/bundled/'));
-});
+		.pipe(gulp.dest('dist/bundled/'))
+);
 
-gulp.task('build:deps:npm:jquery.repeater', function () {
-	return gulp
+gulp.task('build:deps:npm:jquery.repeater', () =>
+	gulp
 		.src('node_modules/jquery.repeater/jquery.repeater.min.js')
-		.pipe(gulp.dest('dist/bundled/'));
-});
+		.pipe(gulp.dest('dist/bundled/'))
+);
 
-gulp.task('build:deps:npm:jQuery-QueryBuilder', function () {
-	return gulp
+gulp.task('build:deps:npm:jQuery-QueryBuilder', () =>
+	gulp
 		.src([
 			'node_modules/jQuery-QueryBuilder/dist/css/query-builder.default.css',
 			'node_modules/jQuery-QueryBuilder/dist/js/query-builder.standalone.js',
 		])
-		.pipe(gulp.dest('dist/bundled/'));
-});
+		.pipe(gulp.dest('dist/bundled/'))
+);
 
-gulp.task('build:deps:npm:select2', function () {
-	return gulp
+gulp.task('build:deps:npm:select2', () =>
+	gulp
 		.src([
 			'node_modules/select2/dist/css/select2.min.css',
 			'node_modules/select2/dist/js/select2.min.js',
 		])
-		.pipe(gulp.dest('dist/bundled/'));
-});
+		.pipe(gulp.dest('dist/bundled/'))
+);
 
 gulp.task(
 	'build:deps:npm',
@@ -237,7 +236,7 @@ gulp.task(
 
 gulp.task('build:deps', gulp.parallel('build:deps:composer', 'build:deps:npm'));
 
-gulp.task('build:js:admin', function () {
+gulp.task('build:js:admin', () => {
 	const tsProject = ts.createProject('tsconfig.json');
 	return gulp
 		.src(['src/ts/admin/*.ts', 'src/d.ts/*.d.ts'])
@@ -247,7 +246,7 @@ gulp.task('build:js:admin', function () {
 		.pipe(gulp.dest('dist/admin/js/'));
 });
 
-gulp.task('build:js:modules:Register:admin', function () {
+gulp.task('build:js:modules:Register:admin', () => {
 	const tsProject = ts.createProject('tsconfig.json');
 	return gulp
 		.src(['src/ts/modules/Register/admin/*.ts', 'src/d.ts/*.d.ts'])
@@ -262,7 +261,7 @@ gulp.task(
 	gulp.parallel('build:js:modules:Register:admin')
 );
 
-gulp.task('build:js:modules:Shortcodes:admin', function () {
+gulp.task('build:js:modules:Shortcodes:admin', () => {
 	const tsProject = ts.createProject('tsconfig.json');
 	return gulp
 		.src(['src/ts/modules/Shortcodes/admin/*.ts', 'src/d.ts/*.d.ts'])
@@ -277,7 +276,7 @@ gulp.task(
 	gulp.parallel('build:js:modules:Shortcodes:admin')
 );
 
-gulp.task('build:js:modules:Visibility:admin', function () {
+gulp.task('build:js:modules:Visibility:admin', () => {
 	const tsProject = ts.createProject('tsconfig.json');
 	return gulp
 		.src(['src/ts/modules/Visibility/admin/*.ts', 'src/d.ts/*.d.ts'])
@@ -301,7 +300,7 @@ gulp.task(
 	)
 );
 
-gulp.task('build:js:rules:admin', function () {
+gulp.task('build:js:rules:admin', () => {
 	const tsProject = ts.createProject('tsconfig.json');
 	return gulp
 		.src(['src/ts/rules/admin/*.ts', 'src/d.ts/*.d.ts'])
@@ -318,23 +317,23 @@ gulp.task(
 	gulp.parallel('build:js:admin', 'build:js:modules', 'build:js:rules')
 );
 
-gulp.task('build:php:base', function () {
-	return gulp.src(['src/php/*.php']).pipe(gulp.dest('dist/'));
-});
+gulp.task('build:php:base', () =>
+	gulp.src(['src/php/*.php']).pipe(gulp.dest('dist/'))
+);
 
-gulp.task('build:php:other', function () {
-	return gulp.src(['src/php/**/*.php']).pipe(gulp.dest('dist/'));
-});
+gulp.task('build:php:other', () =>
+	gulp.src(['src/php/**/*.php']).pipe(gulp.dest('dist/'))
+);
 
 gulp.task('build:php', gulp.parallel('build:php:base', 'build:php:other'));
 
-gulp.task('build:png', function () {
-	return gulp.src(['src/png/**/*.png']).pipe(gulp.dest('dist/src/'));
-});
+gulp.task('build:png', () =>
+	gulp.src(['src/png/**/*.png']).pipe(gulp.dest('dist/src/'))
+);
 
-gulp.task('build:txt', function () {
-	return gulp.src(['src/txt/**/*.txt']).pipe(gulp.dest('dist/'));
-});
+gulp.task('build:txt', () =>
+	gulp.src(['src/txt/**/*.txt']).pipe(gulp.dest('dist/'))
+);
 
 gulp.task(
 	'build',
diff --git a/package-lock.json b/package-lock.json
index f66033cf..e388956c 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -32,6 +32,7 @@
         "eslint-config-prettier": "^9.0.0",
         "eslint-plugin-compat": "^4.2.0",
         "eslint-plugin-deprecation": "^2.0.0",
+        "eslint-plugin-prefer-arrow-functions": "^3.2.4",
         "eslint-plugin-prettier": "^5.0.1",
         "eslint-plugin-simple-import-sort": "^10.0.0",
         "gulp": "^4.0.2",
@@ -5439,6 +5440,15 @@
         }
       }
     },
+    "node_modules/eslint-plugin-prefer-arrow-functions": {
+      "version": "3.2.4",
+      "resolved": "https://registry.npmjs.org/eslint-plugin-prefer-arrow-functions/-/eslint-plugin-prefer-arrow-functions-3.2.4.tgz",
+      "integrity": "sha512-HbPmlbO/iYQeVs2fuShNkGVJDfVfgSd84Vzxv+xlh+nIVoSsZvTj6yOqszw4mtG9JbiqMShVWqbVeoVsejE59w==",
+      "dev": true,
+      "peerDependencies": {
+        "eslint": ">=5.0.0"
+      }
+    },
     "node_modules/eslint-plugin-prettier": {
       "version": "5.0.1",
       "resolved": "https://registry.npmjs.org/eslint-plugin-prettier/-/eslint-plugin-prettier-5.0.1.tgz",
diff --git a/package.json b/package.json
index 810241fb..6b53c7ea 100644
--- a/package.json
+++ b/package.json
@@ -56,6 +56,7 @@
     "eslint-config-prettier": "^9.0.0",
     "eslint-plugin-compat": "^4.2.0",
     "eslint-plugin-deprecation": "^2.0.0",
+    "eslint-plugin-prefer-arrow-functions": "^3.2.4",
     "eslint-plugin-prettier": "^5.0.1",
     "eslint-plugin-simple-import-sort": "^10.0.0",
     "gulp": "^4.0.2",
diff --git a/src/ts/admin/skautis-admin-users-management.ts b/src/ts/admin/skautis-admin-users-management.ts
index d2372e72..40c77424 100644
--- a/src/ts/admin/skautis-admin-users-management.ts
+++ b/src/ts/admin/skautis-admin-users-management.ts
@@ -21,7 +21,7 @@
 				'/cs.json',
 			search: 'Hledat',
 		},
-		initComplete() {
+		initComplete: () => {
 			const searchString = getQueryStringFromUrl(
 				'skautisSearchUsers',
 				window.location.href
@@ -32,7 +32,7 @@
 					$searchButton = $('<button>')
 						.text($dataTable.i18n('search', 'Search'))
 						.addClass('button button-secondary')
-						.on('click', function () {
+						.on('click', () => {
 							const withNonce = updateQueryStringInUrl(
 								skautisIntegrationAdminUsersManagementLocalize.searchNonceName,
 								skautisIntegrationAdminUsersManagementLocalize.searchNonceValue,
@@ -44,7 +44,7 @@
 								withNonce
 							);
 						});
-				$input.on('keyup', function (e) {
+				$input.on('keyup', (e) => {
 					e.preventDefault();
 					if (e.key === 'Enter') {
 						$searchButton.trigger('click');
@@ -57,7 +57,7 @@
 				const $clearButton = $('<button>')
 					.text(skautisIntegrationAdminUsersManagementLocalize.cancel)
 					.addClass('button button-secondary')
-					.on('click', function () {
+					.on('click', () => {
 						$('.dataTables_filter input').val('');
 						window.location.href = updateQueryStringInUrl(
 							'skautisSearchUsers',
diff --git a/src/ts/modules/Register/admin/skautis-modules-register-admin.ts b/src/ts/modules/Register/admin/skautis-modules-register-admin.ts
index ef2030c7..fde03a02 100644
--- a/src/ts/modules/Register/admin/skautis-modules-register-admin.ts
+++ b/src/ts/modules/Register/admin/skautis-modules-register-admin.ts
@@ -22,7 +22,7 @@
 		},
 		hide(deleteElement) {
 			$(this).slideUp(150, deleteElement);
-			setTimeout(function () {
+			setTimeout(() => {
 				if (!$('#repeater').find('[data-repeater-item]').length) {
 					$('.form-table')
 						.find('tr')
diff --git a/src/ts/modules/Shortcodes/admin/skautis-modules-shortcodes-tinymceRulesButton.ts b/src/ts/modules/Shortcodes/admin/skautis-modules-shortcodes-tinymceRulesButton.ts
index 45e3864e..2e343798 100644
--- a/src/ts/modules/Shortcodes/admin/skautis-modules-shortcodes-tinymceRulesButton.ts
+++ b/src/ts/modules/Shortcodes/admin/skautis-modules-shortcodes-tinymceRulesButton.ts
@@ -8,7 +8,7 @@ interface ModalData {
 	rules4: string | null;
 }
 
-(function (): void {
+((): void => {
 	tinymce.addI18n('cs', {
 		shortcode_options: 'Nastavení shortcode',
 		insert_skautis_rules: 'Vložit skautIS pravidlo',
@@ -24,7 +24,7 @@ interface ModalData {
 	});
 	(tinymce as unknown as typeof TinyMCE).PluginManager.add(
 		'skautis_rules',
-		function (editor, url) {
+		(editor, url) => {
 			editor.addButton('skautis_rules', {
 				title: 'insert_skautis_rules',
 				image:
diff --git a/src/ts/modules/Visibility/admin/skautis-modules-visibility-admin.ts b/src/ts/modules/Visibility/admin/skautis-modules-visibility-admin.ts
index 149b4fb3..01183812 100644
--- a/src/ts/modules/Visibility/admin/skautis-modules-visibility-admin.ts
+++ b/src/ts/modules/Visibility/admin/skautis-modules-visibility-admin.ts
@@ -17,11 +17,11 @@
 				},
 				hide(deleteElement) {
 					$(this).slideUp(150, deleteElement);
-					setTimeout(function () {
+					setTimeout(() => {
 						updateAvailableOptions();
 					}, 250);
 				},
-				ready() {
+				ready: () => {
 					reinitSelect2();
 				},
 				isFirstItemUndeletable: true,
diff --git a/src/ts/rules/admin/skautis-rules-admin.ts b/src/ts/rules/admin/skautis-rules-admin.ts
index c0387b45..54652c21 100644
--- a/src/ts/rules/admin/skautis-rules-admin.ts
+++ b/src/ts/rules/admin/skautis-rules-admin.ts
@@ -42,7 +42,7 @@
 						placeholder:
 							skautisIntegrationRulesLocalize.select_placeholder,
 						sorter: (data) =>
-							data.sort(function (a, b) {
+							data.sort((a, b) => {
 								if (
 									typeof a.text.localeCompare === 'function'
 								) {
@@ -53,11 +53,11 @@
 					});
 				});
 		});
-		setTimeout(function () {
+		setTimeout(() => {
 			$('#query_builder').trigger('change');
 		}, 100);
 
-		$('#post').on('submit', function () {
+		$('#post').on('submit', () => {
 			const result = $('#query_builder').get(0)!.queryBuilder.getRules();
 
 			if (!$.isEmptyObject(result)) {