diff --git a/wp-includes/author-template.php b/wp-includes/author-template.php
index 2911366f..bc113b64 100644
--- a/wp-includes/author-template.php
+++ b/wp-includes/author-template.php
@@ -101,7 +101,7 @@ function get_the_modified_author() {
 		 *
 		 * @param string $display_name The author's display name.
 		 */
-		return apply_filters( 'the_modified_author', $last_user->display_name );
+		return apply_filters( 'the_modified_author', $last_user ? $last_user->display_name : '' );
 	}
 }