diff --git a/cli/update-mailbox-quotas.php b/cli/update-mailbox-quotas.php
index 8f0b8b1..bdae8a8 100755
--- a/cli/update-mailbox-quotas.php
+++ b/cli/update-mailbox-quotas.php
@@ -1,100 +1,100 @@
 #!/usr/bin/php
 <?php
 # Copyright (C) 2019, 2020 Valerio Bozzolan
 # KISS Libre Hosting Panel
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU Affero General Public License as
 # published by the Free Software Foundation, either version 3 of the
 # License, or (at your option) any later version.
 #
 # This program is distributed in the hope that it will be useful,
 # but WITHOUT ANY WARRANTY; without even the implied warranty of
 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 # GNU Affero General Public License for more details.
 #
 # You should have received a copy of the GNU General Public License
 # along with this program. If not, see <http://www.gnu.org/licenses/>.
 
 require __DIR__ . '/../load.php';
 
 /**
  * Script to update Mailbox quotas
  *
  * See https://gitpull.it/T101
  */
 
 // get every active domain
 $domains = ( new DomainAPI() )
 	->select( [
 		'domain.domain_ID',
 		'domain_name',
 	] )
 	->whereDomainIsActive()
 	->queryGenerator();
 
 // for each active domain
 foreach( $domains as $domain ) {
 
 	$domain_name = $domain->getDomainName();
 
 	// validate domain name
 	if( strpos( $domain_name, __ ) !== false ) {
 		error( "domain '$domain_name' is bad" );
 		continue;
 	}
 
 	// get every active mailbox of this domain
 	$mailboxes = ( new MailboxAPI() )
 		->select( [
 			'mailbox_ID',
 			'mailbox_username',
 		] )
 		->whereDomain( $domain )
 		->whereMailboxIsActive()
 		->queryGenerator();
 
 	query( 'START TRANSACTION' );
 
 	// for each mailboxes
 	foreach( $mailboxes as $mailbox ) {
 
 		$mailbox_username = $mailbox->getMailboxUsername();
 
 		// validate mailbox name
 		if( strpos( $mailbox_username, __ ) !== false ) {
 			error( "$domain_name.$mailbox_username is bad" );
 			continue;
 		}
 
 		// calculate the quota size
 		$bytes = 0;
 		$expected_path = MAILBOX_BASE_PATH . __ . $domain_name . __ . $mailbox_username;
 		if( file_exists( $expected_path ) ) {
 			$bytes_raw = exec( sprintf(
-				'du --summarize -- %s | cut -f1',
+				'du --summarize --bytes -- %s | cut -f1',
 				escapeshellarg( $expected_path )
 			) );
 
 			$bytes = (int) $bytes_raw;
 		}
 
 		// store the value in the history
 		( new MailboxSizeAPI() )
 			->insertRow( [
 				'mailbox_ID'        => $mailbox->getMailboxID(),
 				'mailboxsize_bytes' => $bytes,
 				new DBCol( 'mailboxsize_date', 'NOW()', '-' ),
 			] );
 
 		// update the denormalized latest Mailbox data
 		( new MailboxAPI() )
 			->whereMailbox( $mailbox )
 			->update( [
 				'mailbox_lastsizebytes' => $bytes,
 			] );
 	}
 
 
 	query( 'COMMIT' );
 }