diff --git a/src/wp-includes/class-wp-textdomain-registry.php b/src/wp-includes/class-wp-textdomain-registry.php
index 4564a6c0bf..fc3994ad15 100644
--- a/src/wp-includes/class-wp-textdomain-registry.php
+++ b/src/wp-includes/class-wp-textdomain-registry.php
@@ -97,7 +97,7 @@ class WP_Textdomain_Registry {
 	 */
 	public function has( $domain ) {
 		return (
-			! empty( $this->current[ $domain ] ) ||
+			isset( $this->current[ $domain ] ) ||
 			empty( $this->all[ $domain ] ) ||
 			in_array( $domain, $this->domains_with_translations, true )
 		);
diff --git a/src/wp-includes/l10n.php b/src/wp-includes/l10n.php
index 080007b869..a0c7bba903 100644
--- a/src/wp-includes/l10n.php
+++ b/src/wp-includes/l10n.php
@@ -834,6 +834,12 @@ function unload_textdomain( $domain, $reloadable = false ) {
 	do_action( 'unload_textdomain', $domain, $reloadable );
 
 	if ( isset( $l10n[ $domain ] ) ) {
+		if ( $l10n[ $domain ] instanceof NOOP_Translations ) {
+			unset( $l10n[ $domain ] );
+
+			return false;
+		}
+
 		unset( $l10n[ $domain ] );
 
 		if ( ! $reloadable ) {
@@ -1307,6 +1313,8 @@ function get_translations_for_domain( $domain ) {
 		$noop_translations = new NOOP_Translations();
 	}
 
+	$l10n[ $domain ] = &$noop_translations;
+
 	return $noop_translations;
 }
 
@@ -1322,7 +1330,7 @@ function get_translations_for_domain( $domain ) {
  */
 function is_textdomain_loaded( $domain ) {
 	global $l10n;
-	return isset( $l10n[ $domain ] );
+	return isset( $l10n[ $domain ] ) && ! $l10n[ $domain ] instanceof NOOP_Translations;
 }
 
 /**
diff --git a/tests/phpunit/tests/l10n/loadTextdomainJustInTime.php b/tests/phpunit/tests/l10n/loadTextdomainJustInTime.php
index 4f29c0c586..3b93d4a975 100644
--- a/tests/phpunit/tests/l10n/loadTextdomainJustInTime.php
+++ b/tests/phpunit/tests/l10n/loadTextdomainJustInTime.php
@@ -121,6 +121,27 @@ class Tests_L10n_LoadTextdomainJustInTime extends WP_UnitTestCase {
 		$this->assertInstanceOf( 'NOOP_Translations', $translations );
 	}
 
+	/**
+	 * @ticket 58321
+	 *
+	 * @covers ::get_translations_for_domain
+	 */
+	public function test_get_translations_for_domain_get_locale_is_called_only_once() {
+		$filter_locale = new MockAction();
+		add_filter( 'locale', array( $filter_locale, 'filter' ) );
+
+		get_translations_for_domain( 'internationalized-plugin' );
+		get_translations_for_domain( 'internationalized-plugin' );
+		get_translations_for_domain( 'internationalized-plugin' );
+		$translations = get_translations_for_domain( 'internationalized-plugin' );
+
+		remove_filter( 'locale', array( $filter_locale, 'filter' ) );
+
+		$this->assertSame( 1, $filter_locale->get_call_count() );
+		$this->assertInstanceOf( 'NOOP_Translations', $translations );
+		$this->assertFalse( is_textdomain_loaded( 'internationalized-plugin' ) );
+	}
+
 	/**
 	 * @ticket 37113
 	 *
diff --git a/tests/phpunit/tests/l10n/wpLocaleSwitcher.php b/tests/phpunit/tests/l10n/wpLocaleSwitcher.php
index 7d61f54d55..1b0b8f796d 100644
--- a/tests/phpunit/tests/l10n/wpLocaleSwitcher.php
+++ b/tests/phpunit/tests/l10n/wpLocaleSwitcher.php
@@ -384,7 +384,7 @@ class Tests_L10n_wpLocaleSwitcher extends WP_UnitTestCase {
 		$locale_switched_user_locale  = switch_to_locale( $user_locale ); // False.
 		$locale_switched_site_locale  = switch_to_locale( $site_locale ); // True.
 		$site_locale_after_switch     = get_locale();
-		$language_header_after_switch = isset( $l10n['default'] ); // en_US
+		$language_header_after_switch = is_textdomain_loaded( 'default' ); // en_US
 
 		restore_current_locale();