diff --git tests/phpunit/tests/functions.php tests/phpunit/tests/functions.php
index d9e3d5f..8ea8fba 100644
--- tests/phpunit/tests/functions.php
+++ tests/phpunit/tests/functions.php
@@ -1301,6 +1301,43 @@ class Tests_Functions extends WP_UnitTestCase {
 							'proper_filename' => false,
 						),
 					),
+					// MP4 Video.
+					array(
+						DIR_TESTDATA . '/uploads/small-video.mp4',
+						'small-video.mp4',
+						array(
+							'ext'             => 'mp4',
+							'type'            => 'video/mp4',
+							'proper_filename' => false,
+						),
+					),
+					array(
+						DIR_TESTDATA . '/uploads/small-audio.mp4',
+						'small-audio.mp4',
+						array(
+							'ext'             => 'm4a',
+							'type'            => 'audio/mpeg',
+							'proper_filename' => 'small-audio.m4a',
+						),
+					),
+					array(
+						DIR_TESTDATA . '/uploads/small-video.ogg',
+						'small-video.ogg',
+						array(
+							'ext'             => 'ogv',
+							'type'            => 'video/ogg',
+							'proper_filename' => 'small-video.ogv',
+						),
+					),
+					array(
+						DIR_TESTDATA . '/uploads/small-audio.ogg',
+						'small-audio.ogg',
+						array(
+							'ext'             => 'ogg',
+							'type'            => 'audio/ogg',
+							'proper_filename' => false,
+						),
+					),
 				)
 			);
 		}