diff --git a/htdocs/accountancy/bookkeeping/balance.php b/htdocs/accountancy/bookkeeping/balance.php
index b27805ca1a7b4..8dc85fb642c8e 100644
--- a/htdocs/accountancy/bookkeeping/balance.php
+++ b/htdocs/accountancy/bookkeeping/balance.php
@@ -475,9 +475,9 @@
 		$resql = $db->query($sql);
 		$opening_balances = array();
 		if ($resql) {
-			$nrows = $resql->num_rows;
+			$nrows = $db->num_rows($resql);
 			for ($i = 0; $i < $nrows; $i++) {
-				$arr = $resql->fetch_array();
+				$arr = $db->fetch_array($resql);
 				$opening_balances["'" . $arr['numero_compte'] . "'"] = $arr['opening_balance'];
 			}
 		}