diff --git a/src/wp-includes/feed.php b/src/wp-includes/feed.php
index 7d585f1136..8dc58d437c 100644
--- a/src/wp-includes/feed.php
+++ b/src/wp-includes/feed.php
@@ -98,6 +98,7 @@ function get_default_feed() {
  */
 function get_wp_title_rss( $deprecated = '–' ) {
 	if ( '–' !== $deprecated ) {
+		/* translators: 1: 'document_title_separator' filter name */
 		_deprecated_argument( __FUNCTION__, '4.4.0', sprintf( __( 'Use the %s filter instead.' ), '<code>document_title_separator</code>' ) );
 	}
 
@@ -123,6 +124,7 @@ function get_wp_title_rss( $deprecated = '&#8211;' ) {
  */
 function wp_title_rss( $deprecated = '&#8211;' ) {
 	if ( '&#8211;' !== $deprecated ) {
+		/* translators: 1: 'document_title_separator' filter name */
 		_deprecated_argument( __FUNCTION__, '4.4.0', sprintf( __( 'Use the %s filter instead.' ), '<code>document_title_separator</code>' ) );
 	}