diff --git a/wp-admin/includes/class-wp-upgrader.php b/wp-admin/includes/class-wp-upgrader.php
index 210df08391..13de05223e 100644
--- a/wp-admin/includes/class-wp-upgrader.php
+++ b/wp-admin/includes/class-wp-upgrader.php
@@ -1225,7 +1225,7 @@ class Core_Upgrader extends WP_Upgrader {
 		$this->strings['copy_failed'] = __('Could not copy files.');
 		$this->strings['copy_failed_space'] = __('Could not copy files. You may have run out of disk space.' );
 		$this->strings['start_rollback'] = __( 'Attempting to roll back to previous version.' );
-		$this->strings['rollback_was_required'] = __( 'Due to an error during updating, WordPress has rolled back to your previous version' );
+		$this->strings['rollback_was_required'] = __( 'Due to an error during updating, WordPress has rolled back to your previous version.' );
 	}
 
 	function upgrade( $current, $args = array() ) {