diff --git a/packages/table-rate-shipping/src/Resolvers/ShippingRateResolver.php b/packages/table-rate-shipping/src/Resolvers/ShippingRateResolver.php
index 9217e63b85..40fbecbcf9 100644
--- a/packages/table-rate-shipping/src/Resolvers/ShippingRateResolver.php
+++ b/packages/table-rate-shipping/src/Resolvers/ShippingRateResolver.php
@@ -118,7 +118,7 @@ public function state($state): self
     /**
      * Set the value for the postcode.
      */
-    public function postcode(string $postcode): self
+    public function postcode(?string $postcode): self
     {
         $this->postcode = $postcode;