diff --git a/tests/unit-tests/coupon/coupon.php b/tests/unit-tests/coupon/coupon.php
index 1cf6411dc41..7476c0fa054 100644
--- a/tests/unit-tests/coupon/coupon.php
+++ b/tests/unit-tests/coupon/coupon.php
@@ -266,7 +266,7 @@ class WC_Tests_Coupon extends WC_Unit_Test_Case {
 		$expired_coupon->set_date_created( time() - 20 );
 		$expired_coupon->set_date_modified( time() - 20 );
 
-		$this->assertInstanceOf( WC_DateTime::class, $valid_coupon->get_date_created() );
+		$this->assertInstanceOf( 'WC_DateTime', $valid_coupon->get_date_created() );
 		$this->assertTrue( $valid_coupon->is_valid() );
 		$this->assertFalse( $expired_coupon->is_valid() );
 		$this->assertEquals( $expired_coupon->get_error_message(), $expired_coupon->get_coupon_error( WC_Coupon::E_WC_COUPON_EXPIRED ) );