diff --git a/wp-includes/post.php b/wp-includes/post.php
index ad79941b4..6ce110ebf 100644
--- a/wp-includes/post.php
+++ b/wp-includes/post.php
@@ -168,12 +168,12 @@ add_action( 'init', 'create_initial_post_types', 0 ); // highest priority
  *
  * @param int $attachment_id Attachment ID.
  * @param bool $unfiltered Whether to apply filters.
- * @return string The file path to the attached file.
+ * @return string|bool The file path to the attached file, or false if the attachment does not exist.
  */
 function get_attached_file( $attachment_id, $unfiltered = false ) {
 	$file = get_post_meta( $attachment_id, '_wp_attached_file', true );
 	// If the file is relative, prepend upload dir
-	if ( 0 !== strpos($file, '/') && !preg_match('|^.:\\\|', $file) && ( ($uploads = wp_upload_dir()) && false === $uploads['error'] ) )
+	if ( $file && 0 !== strpos($file, '/') && !preg_match('|^.:\\\|', $file) && ( ($uploads = wp_upload_dir()) && false === $uploads['error'] ) )
 		$file = $uploads['basedir'] . "/$file";
 	if ( $unfiltered )
 		return $file;