diff --git a/src/Forms/DateField.php b/src/Forms/DateField.php
index 6a24bad34c6..9a759fade6e 100644
--- a/src/Forms/DateField.php
+++ b/src/Forms/DateField.php
@@ -133,6 +133,7 @@ public function getShowCalendar()
 
     /**
      * Set if calendar should be shown on the frontend.
+     * @internal WARNING: Experimental and volatile API.
      *
      * @param bool $show
      * @return $this