diff --git a/src/Model/Resolver/GetCartForCustomer.php b/src/Model/Resolver/GetCartForCustomer.php
index 6deef6c..2bda27b 100644
--- a/src/Model/Resolver/GetCartForCustomer.php
+++ b/src/Model/Resolver/GetCartForCustomer.php
@@ -149,7 +149,7 @@ private function getAppliedTaxes(AddressInterface $address): array
             $taxes = $this->serializer->unserialize($taxes);
         }
 
-        return array_values($taxes);
+        return is_array($taxes) ? array_values($taxes) : [];
     }
 
     /**