Index: src/wp-admin/site-health-info.php
===================================================================
--- src/wp-admin/site-health-info.php	(revision adfe5e271bd04d2a40f35c912b8137e3bba1389a)
+++ src/wp-admin/site-health-info.php	(date 1554192941151)
@@ -68,7 +68,7 @@
 
 	$info         = WP_Debug_Data::debug_data();
 	$english_info = '';
-	if ( 0 !== strpos( get_locale(), 'en' ) ) {
+	if ( 0 !== strpos( get_user_locale(), 'en' ) ) {
 		$english_info = WP_Debug_Data::debug_data( 'en_US' );
 	}
 	?>
Index: src/wp-admin/includes/class-wp-debug-data.php
===================================================================
--- src/wp-admin/includes/class-wp-debug-data.php	(revision adfe5e271bd04d2a40f35c912b8137e3bba1389a)
+++ src/wp-admin/includes/class-wp-debug-data.php	(date 1554192941199)
@@ -36,7 +36,7 @@
 		if ( ! empty( $locale ) ) {
 			// Change the language used for translations
 			if ( function_exists( 'switch_to_locale' ) ) {
-				$original_locale = get_locale();
+				$original_locale = get_user_locale();
 				$switched_locale = switch_to_locale( $locale );
 			}
 		}
@@ -73,7 +73,7 @@
 					),
 					'language'               => array(
 						'label' => __( 'Language' ),
-						'value' => ( ! empty( $locale ) ? $original_locale : get_locale() ),
+						'value' => ( ! empty( $locale ) ? $original_locale : get_user_locale() ),
 					),
 					'home_url'               => array(
 						'label'   => __( 'Home URL' ),