diff --git a/tests/wpunit/OrderMutationsTest.php b/tests/wpunit/OrderMutationsTest.php
index c6f98ba2c..7d828bb9e 100644
--- a/tests/wpunit/OrderMutationsTest.php
+++ b/tests/wpunit/OrderMutationsTest.php
@@ -239,7 +239,7 @@ public function testCreateOrderMutation() {
 			],
 			'paymentMethod'      => 'bacs',
 			'paymentMethodTitle' => 'Direct Bank Transfer',
-			'billing'            => [
+			'billing'            => array(
 				'firstName' => 'May',
 				'lastName'  => 'Parker',
 				'address1'  => '20 Ingram St',
@@ -484,7 +484,7 @@ public function testUpdateOrderMutation() {
 			],
 			'paymentMethod'      => 'bacs',
 			'paymentMethodTitle' => 'Direct Bank Transfer',
-			'billing'            => [
+			'billing'            => array(
 				'firstName' => 'May',
 				'lastName'  => 'Parker',
 				'address1'  => '20 Ingram St',
@@ -809,7 +809,7 @@ public function testDeleteOrderMutation() {
 			],
 			'paymentMethod'      => 'bacs',
 			'paymentMethodTitle' => 'Direct Bank Transfer',
-			'billing'            => [
+			'billing'            => array(
 				'firstName' => 'May',
 				'lastName'  => 'Parker',
 				'address1'  => '20 Ingram St',
@@ -960,7 +960,7 @@ public function testDeleteOrderItemsMutation() {
 			],
 			'paymentMethod'      => 'bacs',
 			'paymentMethodTitle' => 'Direct Bank Transfer',
-			'billing'            => [
+			'billing'            => array(
 				'firstName' => 'May',
 				'lastName'  => 'Parker',
 				'address1'  => '20 Ingram St',