diff --git a/cyr-to-lat.php b/cyr-to-lat.php
index ce1b58f..a19359a 100644
--- a/cyr-to-lat.php
+++ b/cyr-to-lat.php
@@ -10,7 +10,7 @@
  * Plugin Name:       Cyr-To-Lat
  * Plugin URI:        https://wordpress.org/plugins/cyr2lat/
  * Description:       Convert Non-Latin characters in post and term slugs to Latin characters. Useful for creating human-readable URLs. Based on the original plugin by Anton Skorobogatov.
- * Version:           5.1.0
+ * Version:           5.2.0
  * Requires at least: 5.1
  * Requires PHP:      5.6.20
  * Author:            Sergey Biryukov, Mikhail Kobzarev, Igor Gergel
@@ -36,7 +36,7 @@
 /**
  * Plugin version.
  */
-define( 'CYR_TO_LAT_VERSION', '5.1.0' );
+define( 'CYR_TO_LAT_VERSION', '5.2.0' );
 
 /**
  * Path to the plugin dir.
diff --git a/readme.txt b/readme.txt
index d42b2dd..1191056 100644
--- a/readme.txt
+++ b/readme.txt
@@ -3,7 +3,7 @@ Contributors: SergeyBiryukov, mihdan, karevn, webvitaly, kaggdesign
 Tags: cyrillic, belorussian, ukrainian, bulgarian, macedonian, georgian, kazakh, latin, l10n, russian, cyr-to-lat, cyr2lat, rustolat, slugs, translations, transliteration
 Requires at least: 5.1
 Tested up to: 5.8
-Stable tag: 5.1.0
+Stable tag: 5.2.0
 Requires PHP: 5.6.20
 
 Convert Non-Latin characters in post, page and term slugs to Latin characters.
@@ -188,6 +188,9 @@ Yes you can!
 
 == Changelog ==
 
+= 5.2.0 (27.07.2021) =
+* Add support for categories and tags in other languages with wpml.
+
 = 5.1.0 (19.07.2021) =
 * Fix issue-95 - 404 on localized terms created before plugin install.
 * Add cache flushing after batch conversion.
diff --git a/src/php/Settings/Abstracts/SettingsBase.php b/src/php/Settings/Abstracts/SettingsBase.php
index a7de44b..acf94f2 100644
--- a/src/php/Settings/Abstracts/SettingsBase.php
+++ b/src/php/Settings/Abstracts/SettingsBase.php
@@ -217,7 +217,6 @@ protected function parent_slug() {
 	 * Is this the main menu page.
 	 *
 	 * @return bool
-	 * @noinspection PhpPureAttributeCanBeAddedInspection
 	 */
 	protected function is_main_menu_page() {
 		// Main menu page should have empty string as parent slug.
@@ -262,7 +261,7 @@ protected function is_tab() {
 	 *                            With Multisite active this can also include
 	 *                            'network_active' and 'network_only' items.
 	 *
-	 * @return array|mixed Plugin links
+	 * @return array|string[] Plugin links
 	 */
 	public function add_settings_link( array $actions ) {
 		$new_actions = [
diff --git a/src/php/Settings/Converter.php b/src/php/Settings/Converter.php
index 980e334..db0c677 100644
--- a/src/php/Settings/Converter.php
+++ b/src/php/Settings/Converter.php
@@ -87,15 +87,6 @@ protected function section_title() {
 		return '';
 	}
 
-	/**
-	 * Get parent slug.
-	 *
-	 * @return string
-	 */
-	protected function parent_slug() {
-		return 'options-general.php';
-	}
-
 	/**
 	 * Init class hooks.
 	 */
@@ -201,7 +192,7 @@ public function delayed_init_form_fields() {
 	public function delayed_init_settings() {
 		$this->delayed_init_form_fields();
 
-		parent::init_settings();
+		$this->init_settings();
 	}
 
 	/**
diff --git a/src/php/Settings/PluginSettingsBase.php b/src/php/Settings/PluginSettingsBase.php
index fdc9177..f3b92ec 100644
--- a/src/php/Settings/PluginSettingsBase.php
+++ b/src/php/Settings/PluginSettingsBase.php
@@ -29,8 +29,6 @@ protected function plugin_basename() {
 	 * Get plugin url.
 	 *
 	 * @return string
-	 *
-	 * @noinspection PhpPureAttributeCanBeAddedInspection
 	 */
 	protected function plugin_url() {
 		return constant( 'CYR_TO_LAT_URL' );
@@ -40,8 +38,6 @@ protected function plugin_url() {
 	 * Get plugin version.
 	 *
 	 * @return string
-	 *
-	 * @noinspection PhpPureAttributeCanBeAddedInspection
 	 */
 	protected function plugin_version() {
 		return constant( 'CYR_TO_LAT_VERSION' );
diff --git a/src/php/Settings/Settings.php b/src/php/Settings/Settings.php
index 7f603d3..ed37b73 100644
--- a/src/php/Settings/Settings.php
+++ b/src/php/Settings/Settings.php
@@ -48,6 +48,8 @@ public function __construct() {
 
 	/**
 	 * Init class.
+	 *
+	 * @noinspection UnnecessaryCastingInspection
 	 */
 	protected function init() {
 		// Allow to specify MENU_PAGES item as one class, not an array.
diff --git a/src/php/Settings/Tables.php b/src/php/Settings/Tables.php
index 16b48e8..d041058 100644
--- a/src/php/Settings/Tables.php
+++ b/src/php/Settings/Tables.php
@@ -96,16 +96,6 @@ protected function section_title() {
 		return '';
 	}
 
-	/**
-	 * Get parent slug.
-	 *
-	 * @return string
-	 */
-	protected function parent_slug() {
-		// Indicate that it is the main menu page.
-		return 'options-general.php';
-	}
-
 	/**
 	 * Init locales.
 	 */
diff --git a/src/php/background-processes/class-conversion-process.php b/src/php/background-processes/class-conversion-process.php
index 857b66f..a2bfb10 100644
--- a/src/php/background-processes/class-conversion-process.php
+++ b/src/php/background-processes/class-conversion-process.php
@@ -45,7 +45,7 @@ public function __construct( $main ) {
 	 *
 	 * @param mixed $item Queue item to iterate over.
 	 *
-	 * @return mixed
+	 * @return boolean
 	 */
 	protected function task( $item ) {
 		return false;
diff --git a/src/php/background-processes/class-post-conversion-process.php b/src/php/background-processes/class-post-conversion-process.php
index c81b968..003e17a 100644
--- a/src/php/background-processes/class-post-conversion-process.php
+++ b/src/php/background-processes/class-post-conversion-process.php
@@ -52,7 +52,7 @@ public function __construct( $main ) {
 	 *
 	 * @param stdClass $post Queue item to iterate over.
 	 *
-	 * @return mixed
+	 * @return boolean
 	 * @noinspection PhpParameterNameChangedDuringInheritanceInspection
 	 */
 	protected function task( $post ) {
diff --git a/src/php/background-processes/class-term-conversion-process.php b/src/php/background-processes/class-term-conversion-process.php
index ac7c008..fa12fce 100644
--- a/src/php/background-processes/class-term-conversion-process.php
+++ b/src/php/background-processes/class-term-conversion-process.php
@@ -52,7 +52,7 @@ public function __construct( $main ) {
 	 *
 	 * @param stdClass $term Queue item to iterate over.
 	 *
-	 * @return mixed
+	 * @return boolean
 	 * @noinspection PhpParameterNameChangedDuringInheritanceInspection
 	 */
 	protected function task( $term ) {
diff --git a/src/php/class-conversion-tables.php b/src/php/class-conversion-tables.php
index 3be3f43..1603643 100644
--- a/src/php/class-conversion-tables.php
+++ b/src/php/class-conversion-tables.php
@@ -1203,7 +1203,6 @@ public static function get( $locale = '' ) {
 	 * On MacOS, files containing characters in the table, are sometimes encoded improperly.
 	 *
 	 * @return array
-	 * @noinspection PhpArrayShapeAttributeCanBeAddedInspection
 	 */
 	public static function get_fix_table_for_mac() {
 		/**
diff --git a/src/php/class-main.php b/src/php/class-main.php
index 8770e82..83d90ff 100644
--- a/src/php/class-main.php
+++ b/src/php/class-main.php
@@ -11,6 +11,8 @@
 
 namespace Cyr_To_Lat;
 
+use Polylang;
+use SitePress;
 use WP_Error;
 use wpdb;
 use Exception;
@@ -153,9 +155,15 @@ public function init_hooks() {
 		add_filter( 'pre_insert_term', [ $this, 'pre_insert_term_filter' ], PHP_INT_MAX, 2 );
 		add_filter( 'get_terms_args', [ $this, 'get_terms_args_filter' ], PHP_INT_MAX, 2 );
 
-		if ( class_exists( 'Polylang' ) ) {
+		if ( class_exists( Polylang::class ) ) {
 			add_filter( 'locale', [ $this, 'pll_locale_filter' ] );
 		}
+
+		if ( class_exists( SitePress::class ) ) {
+			// We cannot use locale filter here
+			// as WPML reverts locale at PHP_INT_MAX in \WPML\ST\MO\Hooks\LanguageSwitch::filterLocale.
+			add_filter( 'ctl_locale', [ $this, 'wpml_locale_filter' ], - PHP_INT_MAX );
+		}
 	}
 
 	/**
@@ -390,7 +398,7 @@ private function is_gutenberg_editor_active() {
 	 * @param array $data    An array of slashed post data.
 	 * @param array $postarr An array of sanitized, but otherwise unmodified post data.
 	 *
-	 * @return mixed
+	 * @return array
 	 * @noinspection PhpUnusedParameterInspection
 	 */
 	public function sanitize_post_name( $data, $postarr = [] ) {
@@ -579,6 +587,24 @@ private function pll_locale_filter_with_term() {
 		return $pll_get_term_language;
 	}
 
+	/**
+	 * Locale filter for WPML.
+	 *
+	 * @param string $locale Locale.
+	 *
+	 * @return string
+	 */
+	public function wpml_locale_filter( $locale ) {
+		$language_code = wpml_get_current_language();
+		$languages     = apply_filters( 'wpml_active_languages', null );
+
+		if ( isset( $languages[ $language_code ] ) ) {
+			return $languages[ $language_code ]['default_locale'];
+		}
+
+		return $locale;
+	}
+
 	/**
 	 * Changes array of items into string of items, separated by comma and sql-escaped
 	 *
@@ -593,14 +619,15 @@ private function pll_locale_filter_with_term() {
 	public function prepare_in( $items, $format = '%s' ) {
 		global $wpdb;
 
-		$items    = (array) $items;
-		$how_many = count( $items );
+		$prepared_in = '';
+		$items       = (array) $items;
+		$how_many    = count( $items );
+
 		if ( $how_many > 0 ) {
 			$placeholders    = array_fill( 0, $how_many, $format );
 			$prepared_format = implode( ',', $placeholders );
-			$prepared_in     = $wpdb->prepare( $prepared_format, $items ); // phpcs:ignore WordPress.DB.PreparedSQL.NotPrepared
-		} else {
-			$prepared_in = '';
+			// phpcs:ignore WordPress.DB.PreparedSQL.NotPrepared
+			$prepared_in = $wpdb->prepare( $prepared_format, $items );
 		}
 
 		return $prepared_in;
diff --git a/src/php/class-requirements.php b/src/php/class-requirements.php
index 50dd72d..b3e3981 100644
--- a/src/php/class-requirements.php
+++ b/src/php/class-requirements.php
@@ -182,8 +182,6 @@ private function is_max_input_vars_required() {
 
 		/**
 		 * Try to fix max_input_vars.
-		 *
-		 * @noinspection PhpStrFunctionsInspection
 		 */
 		protected function try_to_fix_max_input_vars() {
 			$user_ini_filename = $this->get_user_ini_filename();
@@ -225,7 +223,6 @@ static function ( $line ) {
 		 * Get .user.ini filename.
 		 *
 		 * @return string
-		 * @noinspection PhpPureAttributeCanBeAddedInspection
 		 */
 		private function get_user_ini_filename() {
 			return ABSPATH . 'wp-admin/' . ini_get( 'user_ini.filename' );
@@ -238,7 +235,7 @@ private function ask_to_increase_max_input_vars() {
 			$message = __( 'Please increase max input vars limit up to 1500.', 'cyr2lat' );
 
 			$message .= '<br>';
-			$message .= __( 'See: <a href="http://sevenspark.com/docs/ubermenu-3/faqs/menu-item-limit" target="_blank">Increasing max input vars limit.</a>', 'cyr2lat' );
+			$message .= __( 'See: <a href="https://sevenspark.com/docs/ubermenu-3/faqs/menu-item-limit" target="_blank">Increasing max input vars limit.</a>', 'cyr2lat' );
 
 			$this->admin_notices->add_notice(
 				$message,
diff --git a/tests/phpunit/bootstrap.php b/tests/phpunit/bootstrap.php
index 93a64b6..4418110 100644
--- a/tests/phpunit/bootstrap.php
+++ b/tests/phpunit/bootstrap.php
@@ -42,7 +42,7 @@
 /**
  * Plugin version.
  */
-define( 'CYR_TO_LAT_TEST_VERSION', '5.1.0' );
+define( 'CYR_TO_LAT_TEST_VERSION', '5.2.0' );
 
 /**
  * Path to the plugin dir.
diff --git a/tests/phpunit/tests/class-test-main.php b/tests/phpunit/tests/class-test-main.php
index 6651f8f..34ff7f8 100644
--- a/tests/phpunit/tests/class-test-main.php
+++ b/tests/phpunit/tests/class-test-main.php
@@ -227,11 +227,12 @@ function ( $name ) {
 	/**
 	 * Test init_hooks()
 	 *
-	 * @param string $polylang Polylang is active.
+	 * @param boolean $polylang  Polylang is active.
+	 * @param boolean $sitepress WPML is active.
 	 *
 	 * @dataProvider dp_test_init_hooks
 	 */
-	public function test_init_hooks( $polylang ) {
+	public function test_init_hooks( $polylang, $sitepress ) {
 		$subject = Mockery::mock( Main::class )->makePartial();
 
 		WP_Mock::expectFilterAdded( 'sanitize_title', [ $subject, 'sanitize_title' ], 9, 3 );
@@ -242,20 +243,31 @@ public function test_init_hooks( $polylang ) {
 
 		FunctionMocker::replace(
 			'class_exists',
-			function ( $class ) use ( $polylang ) {
+			function ( $class ) use ( $polylang, $sitepress ) {
 				if ( 'Polylang' === $class ) {
 					return $polylang;
 				}
 
+				if ( 'SitePress' === $class ) {
+					return $sitepress;
+				}
+
 				return null;
 			}
 		);
+
 		if ( $polylang ) {
 			WP_Mock::expectFilterAdded( 'locale', [ $subject, 'pll_locale_filter' ] );
 		} else {
 			WP_Mock::expectFilterNotAdded( 'locale', [ $subject, 'pll_locale_filter' ] );
 		}
 
+		if ( $sitepress ) {
+			WP_Mock::expectFilterAdded( 'ctl_locale', [ $subject, 'wpml_locale_filter' ], - PHP_INT_MAX );
+		} else {
+			WP_Mock::expectFilterNotAdded( 'ctl_locale', [ $subject, 'wpml_locale_filter' ] );
+		}
+
 		$subject->init_hooks();
 	}
 
@@ -266,8 +278,10 @@ function ( $class ) use ( $polylang ) {
 	 */
 	public function dp_test_init_hooks() {
 		return [
-			[ true ],
-			[ false ],
+			[ false, false ],
+			[ true, false ],
+			[ false, true ],
+			[ true, true ],
 		];
 	}
 
@@ -1069,6 +1083,91 @@ function ( $type, $var_name, $filter ) use ( $term_lang_choice ) {
 		self::assertSame( $pll_locale, $subject->pll_locale_filter( $locale ) );
 	}
 
+	/**
+	 * Test wpml_locale_filter().
+	 *
+	 * @param string $locale        Current locale.
+	 * @param string $language_code Current language code.
+	 * @param string $expected      Expected.
+	 *
+	 * @dataProvider dp_test_wpml_locale_filter
+	 */
+	public function test_wpml_locale_filter( $locale, $language_code, $expected ) {
+		$languages = [
+			'be' =>
+				[
+					'code'           => 'be',
+					'id'             => '64',
+					'english_name'   => 'Belarusian',
+					'native_name'    => 'Belarusian',
+					'major'          => '0',
+					'active'         => '1',
+					'default_locale' => 'be_BY',
+					'encode_url'     => '0',
+					'tag'            => 'be',
+					'display_name'   => 'Belarusian',
+				],
+			'en' =>
+				[
+					'code'           => 'en',
+					'id'             => '1',
+					'english_name'   => 'English',
+					'native_name'    => 'English',
+					'major'          => '1',
+					'active'         => '1',
+					'default_locale' => 'en_US',
+					'encode_url'     => '0',
+					'tag'            => 'en',
+					'display_name'   => 'English',
+				],
+			'ru' =>
+				[
+					'code'           => 'ru',
+					'id'             => '46',
+					'english_name'   => 'Russian',
+					'native_name'    => 'Русский',
+					'major'          => '1',
+					'active'         => '1',
+					'default_locale' => 'ru_RU',
+					'encode_url'     => '0',
+					'tag'            => 'ru',
+					'display_name'   => 'Russian',
+				],
+			'uk' =>
+				[
+					'code'           => 'uk',
+					'id'             => '55',
+					'english_name'   => 'Ukrainian',
+					'native_name'    => 'Ukrainian',
+					'major'          => '0',
+					'active'         => '1',
+					'default_locale' => 'uk',
+					'encode_url'     => '0',
+					'tag'            => 'uk',
+					'display_name'   => 'Ukrainian',
+				],
+		];
+
+		WP_Mock::userFunction( 'wpml_get_current_language' )->with()->andReturn( $language_code );
+		WP_Mock::onFilter( 'wpml_active_languages' )->with( null )->reply( $languages );
+
+		$subject = Mockery::mock( Main::class )->makePartial();
+
+		self::assertSame( $expected, $subject->wpml_locale_filter( $locale ) );
+	}
+
+	/**
+	 * Data provider for test_wpml_locale_filter().
+	 *
+	 * @return array
+	 */
+	public function dp_test_wpml_locale_filter() {
+		return [
+			'Existing language code, return locale from wpml' => [ 'en_US', 'ru', 'ru_RU' ],
+			'Not existing language code, return from current' => [ 'en_US', 'some', 'en_US' ],
+		];
+	}
+
 	/**
 	 * Test prepare_in()
 	 *
diff --git a/tests/phpunit/tests/class-test-requirements.php b/tests/phpunit/tests/class-test-requirements.php
index fdcdd90..20c17ab 100644
--- a/tests/phpunit/tests/class-test-requirements.php
+++ b/tests/phpunit/tests/class-test-requirements.php
@@ -283,7 +283,7 @@ public function test_vars_requirements_not_met( $within_timeout, $content, $expe
 			$message = 'Please increase max input vars limit up to 1500.';
 
 			$message .= '<br>';
-			$message .= 'See: <a href="http://sevenspark.com/docs/ubermenu-3/faqs/menu-item-limit" target="_blank">Increasing max input vars limit.</a>';
+			$message .= 'See: <a href="https://sevenspark.com/docs/ubermenu-3/faqs/menu-item-limit" target="_blank">Increasing max input vars limit.</a>';
 		}
 
 		$admin_notices->shouldReceive( 'add_notice' )->with( $message, 'notice notice-error', $screen_ids );
@@ -435,7 +435,7 @@ function ( $arg ) use ( $max_input_vars, $user_ini_filename, $ini_ttl ) {
 		$message = 'Please increase max input vars limit up to 1500.';
 
 		$message .= '<br>';
-		$message .= 'See: <a href="http://sevenspark.com/docs/ubermenu-3/faqs/menu-item-limit" target="_blank">Increasing max input vars limit.</a>';
+		$message .= 'See: <a href="https://sevenspark.com/docs/ubermenu-3/faqs/menu-item-limit" target="_blank">Increasing max input vars limit.</a>';
 
 		$admin_notices->shouldReceive( 'add_notice' )->with( $message, 'notice notice-error', $screen_ids );