diff --git a/wp-includes/media.php b/wp-includes/media.php
index 699d7c9216..fc5508de48 100644
--- a/wp-includes/media.php
+++ b/wp-includes/media.php
@@ -2749,7 +2749,11 @@ function get_attachment_taxonomies( $attachment, $output = 'names' ) {
 		}
 	}
 
-	return array_unique($taxonomies);
+	if ( 'names' === $output ) {
+		$taxonomies = array_unique( $taxonomies );
+	}
+
+	return $taxonomies;
 }
 
 /**
diff --git a/wp-includes/version.php b/wp-includes/version.php
index ae8cdfea9d..2a6744b6a6 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.7-alpha-38436';
+$wp_version = '4.7-alpha-38437';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.