diff --git a/snappymail/v/0.0.0/app/libraries/MailSo/Imap/FolderInformation.php b/snappymail/v/0.0.0/app/libraries/MailSo/Imap/FolderInformation.php
index e0a73da15..c490f3371 100644
--- a/snappymail/v/0.0.0/app/libraries/MailSo/Imap/FolderInformation.php
+++ b/snappymail/v/0.0.0/app/libraries/MailSo/Imap/FolderInformation.php
@@ -60,6 +60,7 @@ class FolderInformation implements \JsonSerializable
 			\in_array($sFlag, $this->Flags);
 	}
 
+	#[\ReturnTypeWillChange]
 	public function jsonSerialize()
 	{
 		$result = array(