diff --git a/lib/public/Share/IShare.php b/lib/public/Share/IShare.php
index 1e40d7f665..4bd290d66c 100644
--- a/lib/public/Share/IShare.php
+++ b/lib/public/Share/IShare.php
@@ -110,6 +110,11 @@ interface IShare {
 	 */
 	public const TYPE_DECK = 12;
 
+	/**
+	 * @internal 21.00
+	 */
+	public const TYPE_DECK_USER = 13;
+
 	/**
 	 * @since 18.0.0
 	 */