diff --git a/src/wp-includes/query.php b/src/wp-includes/query.php
index 988787a96e..e304bdefaf 100644
--- a/src/wp-includes/query.php
+++ b/src/wp-includes/query.php
@@ -1468,6 +1468,7 @@ class WP_Query {
 	 * @since 4.5.0 Removed the `$comments_popup` parameter.
 	 *              Introduced the `$comment_status` and `$ping_status` parameters.
 	 *              Introduced `RAND(x)` syntax for `$orderby`, which allows an integer seed value to random sorts.
+	 * @since 4.6.0 Added 'post_name__in' support for `$orderby`.
 	 * @access public
 	 *
 	 * @param string|array $query {
@@ -1523,7 +1524,8 @@ class WP_Query {
 	 *                                                 'title', 'modified', 'menu_order', 'parent', 'ID', 'rand',
 	 *                                                 'RAND(x)' (where 'x' is an integer seed value),
 	 *                                                 'comment_count', 'meta_value', 'meta_value_num', 'post__in',
-	 *                                                 and the array keys of `$meta_query`.
+	 *                                                 'post_name__in', 'post_parent__in', and the array keys
+	 *                                                 of `$meta_query`.
 	 *     @type int          $p                       Post ID.
 	 *     @type int          $page                    Show the number of posts that would show up on page X of a
 	 *                                                 static front page.
@@ -2745,7 +2747,8 @@ class WP_Query {
 			$where .= " AND $wpdb->posts.post_name = '" . $q['attachment'] . "'";
 		} elseif ( is_array( $q['post_name__in'] ) && ! empty( $q['post_name__in'] ) ) {
 			$q['post_name__in'] = array_map( 'sanitize_title_for_query', $q['post_name__in'] );
-			$where .= " AND $wpdb->posts.post_name IN ('" . implode( "' ,'", $q['post_name__in'] ) . "')";
+			$post_name__in = "'" . implode( "','", $q['post_name__in'] ) . "'";
+			$where .= " AND $wpdb->posts.post_name IN ($post_name__in)";
 		}
 
 		// If an attachment is requested by number, let it supersede any post number.
@@ -2963,6 +2966,8 @@ class WP_Query {
 			$orderby = "FIELD( {$wpdb->posts}.ID, $post__in )";
 		} elseif ( $q['orderby'] == 'post_parent__in' && ! empty( $post_parent__in ) ) {
 			$orderby = "FIELD( {$wpdb->posts}.post_parent, $post_parent__in )";
+		} elseif ( $q['orderby'] == 'post_name__in' && ! empty( $post_name__in ) ) {
+			$orderby = "FIELD( {$wpdb->posts}.post_name, $post_name__in )";
 		} else {
 			$orderby_array = array();
 			if ( is_array( $q['orderby'] ) ) {
diff --git a/tests/phpunit/tests/post/query.php b/tests/phpunit/tests/post/query.php
index a2a6dff4db..acc8e4e4e1 100644
--- a/tests/phpunit/tests/post/query.php
+++ b/tests/phpunit/tests/post/query.php
@@ -178,6 +178,29 @@ class Tests_Post_Query extends WP_UnitTestCase {
 		$this->assertEqualSets( $ordered, wp_list_pluck( $attached->posts, 'ID' ) );
 	}
 
+	/**
+	 * @ticket 36515
+	 */
+	public function test_post_name__in_ordering() {
+		$post_id1 = self::factory()->post->create( array( 'post_name' => 'id-1', 'post_type' => 'page' ) );
+		$post_id2 = self::factory()->post->create( array( 'post_name' => 'id-2', 'post_type' => 'page' ) );
+		$post_id3 = self::factory()->post->create( array(
+			'post_name' => 'id-3',
+			'post_type' => 'page',
+			'post_parent' => $post_id2
+		) );
+
+		$ordered = array( 'id-2', 'id-3', 'id-1' );
+
+		$q = new WP_Query( array(
+			'post_type' => 'any',
+			'post_name__in' => $ordered,
+			'orderby' => 'post_name__in'
+		) );
+
+		$this->assertSame( $ordered, wp_list_pluck( $q->posts, 'post_name' ) );
+	}
+
 	function test_post_status() {
 		$statuses1 = get_post_stati();
 		$this->assertContains( 'auto-draft', $statuses1 );