diff --git a/lib/DateTimeImmutable.php b/lib/DateTimeImmutable.php
index b6bc9908..f1113998 100644
--- a/lib/DateTimeImmutable.php
+++ b/lib/DateTimeImmutable.php
@@ -240,6 +240,9 @@ public static function createFromMutable($dateTime): self
         return self::createFromRegular($date);
     }
 
+    /**
+     * @return DateTimeImmutable
+     */
     public static function createFromInterface(\DateTimeInterface $object): self
     {
         if ($object instanceof \DateTime) {