diff --git a/src/functions.php b/src/functions.php
index bdc29206..1c58b23f 100644
--- a/src/functions.php
+++ b/src/functions.php
@@ -118,8 +118,8 @@ function serverList($file)
 /**
  * Set task description.
  *
- * @param ?string $title
- * @return ?string
+ * @param string $title
+ * @return string
  */
 function desc($title = null)
 {