diff --git a/src/Cart.php b/src/Cart.php
index f71b96b..1d26cb3 100644
--- a/src/Cart.php
+++ b/src/Cart.php
@@ -579,7 +579,7 @@ public function getRoundingAmount($type = '~'): Decimal
     {
         $this->getTotal($type);
 
-        return $this->roundingAmount;
+        return $this->roundingAmount ?? Decimal::fromInteger(0);
     }
 
     /**