diff --git a/src/wp-includes/feed.php b/src/wp-includes/feed.php
index d56ce8b18e..0b84cc10a5 100644
--- a/src/wp-includes/feed.php
+++ b/src/wp-includes/feed.php
@@ -526,17 +526,17 @@ function atom_enclosure() {
 
 				$mimes = get_allowed_mime_types();
 
-				// Parse url
+				// Parse URL.
 				if ( isset( $enclosure[0] ) && is_string( $enclosure[0] ) ) {
 					$url = trim( $enclosure[0] );
 				}
 
-				// Parse length and type
-				foreach ( range( 1, 2 ) as $i ) {
+				// Parse length and type.
+				for ( $i = 1; $i <= 2; $i++ ) {
 					if ( isset( $enclosure[ $i ] ) ) {
 						if ( is_numeric( $enclosure[ $i ] ) ) {
 							$length = trim( $enclosure[ $i ] );
-						} elseif ( in_array( $enclosure[ $i ], $mimes ) ) {
+						} elseif ( in_array( $enclosure[ $i ], $mimes, true ) ) {
 							$type = trim( $enclosure[ $i ] );
 						}
 					}
@@ -548,6 +548,7 @@ function atom_enclosure() {
 					esc_attr( $length ),
 					esc_attr( $type )
 				);
+
 				/**
 				 * Filters the atom enclosure HTML link tag for the current post.
 				 *
diff --git a/tests/phpunit/tests/feed/atom.php b/tests/phpunit/tests/feed/atom.php
index 026f5eecc1..55a428e586 100644
--- a/tests/phpunit/tests/feed/atom.php
+++ b/tests/phpunit/tests/feed/atom.php
@@ -207,12 +207,13 @@ class Tests_Feeds_Atom extends WP_UnitTestCase {
 	}
 
 	/**
-	 * @test 33591
+	 * @ticket 33591
 	 */
 	function test_atom_enclosure_with_extended_url_length_type_parsing() {
 		$enclosures = array(
 			array(
-				'actual'   => "https://wordpress.dev/wp-content/uploads/2017/09/movie.mp4\n318465\nvideo/mp4",     // url length type
+				// URL, length, type.
+				'actual'   => "https://wordpress.dev/wp-content/uploads/2017/09/movie.mp4\n318465\nvideo/mp4",
 				'expected' => array(
 					'href'   => 'https://wordpress.dev/wp-content/uploads/2017/09/movie.mp4',
 					'length' => 318465,
@@ -220,7 +221,8 @@ class Tests_Feeds_Atom extends WP_UnitTestCase {
 				),
 			),
 			array(
-				'actual'   => "https://wordpress.dev/wp-content/uploads/2017/09/movie.mp4\nvideo/mp4\n318465",     // url type length
+				// URL, type, length.
+				'actual'   => "https://wordpress.dev/wp-content/uploads/2017/09/movie.mp4\nvideo/mp4\n318465",
 				'expected' => array(
 					'href'   => 'https://wordpress.dev/wp-content/uploads/2017/09/movie.mp4',
 					'length' => 318465,
@@ -228,7 +230,8 @@ class Tests_Feeds_Atom extends WP_UnitTestCase {
 				),
 			),
 			array(
-				'actual'   => "https://wordpress.dev/wp-content/uploads/2017/09/movie.mp4\n318465",                // url length
+				// URL, length.
+				'actual'   => "https://wordpress.dev/wp-content/uploads/2017/09/movie.mp4\n318465",
 				'expected' => array(
 					'href'   => 'https://wordpress.dev/wp-content/uploads/2017/09/movie.mp4',
 					'length' => 318465,
@@ -236,7 +239,8 @@ class Tests_Feeds_Atom extends WP_UnitTestCase {
 				),
 			),
 			array(
-				'actual'   => "https://wordpress.dev/wp-content/uploads/2017/01/audio.mp3\n\naudio/mpeg",          // url type
+				// URL, type.
+				'actual'   => "https://wordpress.dev/wp-content/uploads/2017/01/audio.mp3\n\naudio/mpeg",
 				'expected' => array(
 					'href'   => 'https://wordpress.dev/wp-content/uploads/2017/01/audio.mp3',
 					'length' => 0,
@@ -244,7 +248,8 @@ class Tests_Feeds_Atom extends WP_UnitTestCase {
 				),
 			),
 			array(
-				'actual'   => 'https://wordpress.dev/wp-content/uploads/2016/01/test.mp4',                         // url
+				// URL.
+				'actual'   => 'https://wordpress.dev/wp-content/uploads/2016/01/test.mp4',
 				'expected' => array(
 					'href'   => 'https://wordpress.dev/wp-content/uploads/2016/01/test.mp4',
 					'length' => 0,