diff --git a/modules/ppcp-wc-gateway/resources/js/pay-upon-invoice.js b/modules/ppcp-wc-gateway/resources/js/pay-upon-invoice.js
index 4efb00cb1..1e73653b9 100644
--- a/modules/ppcp-wc-gateway/resources/js/pay-upon-invoice.js
+++ b/modules/ppcp-wc-gateway/resources/js/pay-upon-invoice.js
@@ -23,6 +23,9 @@ window.addEventListener('load', function() {
             'f': FraudNetConfig.f,
             's': FraudNetConfig.s
         };
+        if(FraudNetConfig.sandbox === '1') {
+            configuration.sandbox = true;
+        }
 
         script.text = JSON.stringify(configuration);
         document.body.appendChild(script);
diff --git a/modules/ppcp-wc-gateway/src/Gateway/PayUponInvoice/PayUponInvoice.php b/modules/ppcp-wc-gateway/src/Gateway/PayUponInvoice/PayUponInvoice.php
index 0efa289b6..92d4ea974 100644
--- a/modules/ppcp-wc-gateway/src/Gateway/PayUponInvoice/PayUponInvoice.php
+++ b/modules/ppcp-wc-gateway/src/Gateway/PayUponInvoice/PayUponInvoice.php
@@ -283,8 +283,9 @@ class PayUponInvoice {
 			'ppcp-pay-upon-invoice',
 			'FraudNetConfig',
 			array(
-				'f' => $this->fraud_net->session_id(),
-				's' => $this->fraud_net->source_website_id(),
+				'f'       => $this->fraud_net->session_id(),
+				's'       => $this->fraud_net->source_website_id(),
+				'sandbox' => $this->environment->current_environment_is( Environment::SANDBOX ),
 			)
 		);
 	}