diff --git a/htdocs/public/payment/paymentok.php b/htdocs/public/payment/paymentok.php
index 81fac152717..6cfc2e4e81b 100644
--- a/htdocs/public/payment/paymentok.php
+++ b/htdocs/public/payment/paymentok.php
@@ -121,7 +121,7 @@ if (preg_match('/PM=([^\.]+)/', $FULLTAG, $reg)) {
 	$paymentmethod = $reg[1];
 }
 if (empty($paymentmethod)) {
-	dol_print_error(null, 'The back url does not contains a parameter fulltag that should help us to find the payment method used');
+	dol_print_error(null, 'The callback url does not contains a parameter fulltag that should help us to find the payment method used');
 	exit;
 }
 
@@ -250,7 +250,7 @@ print '<br><br><br>';
 
 
 if (isModEnabled('paypal')) {
-	if ($paymentmethod == 'paypal') {							// We call this page only if payment is ok on payment system
+	if ($paymentmethod === 'paypal') {							// We call this page only if payment is ok on payment system
 		if ($PAYPALTOKEN) {
 			// Get on url call
 			$onlinetoken        = $PAYPALTOKEN;
@@ -330,14 +330,14 @@ if (isModEnabled('paypal')) {
 }
 
 if (isModEnabled('paybox')) {
-	if ($paymentmethod == 'paybox') {
+	if ($paymentmethod === 'paybox') {
 		// TODO Add a check to validate that payment is ok.
 		$ispaymentok = true; // We call this page only if payment is ok on payment system
 	}
 }
 
 if (isModEnabled('stripe')) {
-	if ($paymentmethod == 'stripe') {
+	if ($paymentmethod === 'stripe') {
 		// TODO Add a check to validate that payment is ok. We can request Stripe with payment_intent and payment_intent_client_secret
 		$ispaymentok = true; // We call this page only if payment is ok on payment system
 	}