diff --git a/htdocs/public/payment/paymentko.php b/htdocs/public/payment/paymentko.php
index a8ae18fb64d28..3f6f7c8a7c941 100644
--- a/htdocs/public/payment/paymentko.php
+++ b/htdocs/public/payment/paymentko.php
@@ -110,6 +110,7 @@
 }
 
 // Detect $ws
+$reg_ws = array();
 $ws = preg_match('/WS=([^\.]+)/', $FULLTAG, $reg_ws) ? $reg_ws[1] : 0;
 if ($ws) {
 	dol_syslog("Paymentko.php page is invoked from a website with ref ".$ws.". It performs actions and then redirects back to this website. A page with ref paymentko must be created for this website.", LOG_DEBUG, 0, '_payment');
diff --git a/htdocs/public/payment/paymentok.php b/htdocs/public/payment/paymentok.php
index 972c78675ba7d..eb08a8a82798d 100644
--- a/htdocs/public/payment/paymentok.php
+++ b/htdocs/public/payment/paymentok.php
@@ -133,6 +133,7 @@
 dol_syslog("***** paymentok.php is called paymentmethod=".$paymentmethod." FULLTAG=".$FULLTAG." REQUEST_URI=".$_SERVER["REQUEST_URI"], LOG_DEBUG, 0, '_payment');
 
 // Detect $ws
+$reg_ws = array();
 $ws = preg_match('/WS=([^\.]+)/', $FULLTAG, $reg_ws) ? $reg_ws[1] : 0;
 if ($ws) {
 	dol_syslog("Paymentok.php page is invoked from a website with ref ".$ws.". It performs actions and then redirects back to this website. A page with ref paymentok must be created for this website.", LOG_DEBUG, 0, '_payment');