diff --git a/snappymail/v/0.0.0/app/libraries/MailSo/Imap/ImapClient.php b/snappymail/v/0.0.0/app/libraries/MailSo/Imap/ImapClient.php
index 378e97dee..8dbcb2cec 100644
--- a/snappymail/v/0.0.0/app/libraries/MailSo/Imap/ImapClient.php
+++ b/snappymail/v/0.0.0/app/libraries/MailSo/Imap/ImapClient.php
@@ -577,7 +577,7 @@ class ImapClient extends \MailSo\Net\NetClient
 	 */
 	public function FolderHierarchyDelimiter(string $sFolderName = '') : ?string
 	{
-		$oResponse = $this->SendRequestGetResponse('LIST', ['""', $this->EscapeString($sParentFolderName)]);
+		$oResponse = $this->SendRequestGetResponse('LIST', ['""', $this->EscapeString($sFolderName)]);
 		return ('LIST' === $oResponse[0]->ResponseList[1]) ? $oResponse[0]->ResponseList[3] : null;
 	}