diff --git a/includes/class-wc-order-item-tax.php b/includes/class-wc-order-item-tax.php
index 38f2761abc9..e1fa89eb756 100644
--- a/includes/class-wc-order-item-tax.php
+++ b/includes/class-wc-order-item-tax.php
@@ -27,7 +27,7 @@ class WC_Order_Item_Tax extends WC_Order_Item {
 		'compound'           => false,
 		'tax_total'          => 0,
 		'shipping_tax_total' => 0,
-		'rate_percent'       => 0.0,
+		'rate_percent'       => null,
 	);
 
 	/*