From 1d341efa8875779b266c00bee84c9d88f2037c59 Mon Sep 17 00:00:00 2001
From: Anton Evers <anton@eve.rs>
Date: Tue, 14 Nov 2017 09:22:10 +0100
Subject: [PATCH] use InvoiceInterface instead of Invoice model to check if an
 invoice is set on the credit memo

---
 app/code/Magento/Sales/Model/Order/Creditmemo.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/app/code/Magento/Sales/Model/Order/Creditmemo.php b/app/code/Magento/Sales/Model/Order/Creditmemo.php
index 3cf4d01727338..64b903fe5b5c1 100644
--- a/app/code/Magento/Sales/Model/Order/Creditmemo.php
+++ b/app/code/Magento/Sales/Model/Order/Creditmemo.php
@@ -389,7 +389,7 @@ public function canRefund()
      */
     public function getInvoice()
     {
-        if (!$this->getData('invoice') instanceof \Magento\Sales\Model\Order\Invoice && $this->getInvoiceId()) {
+        if (!$this->getData('invoice') instanceof \Magento\Sales\Api\Data\InvoiceInterface && $this->getInvoiceId()) {
             $this->setInvoice($this->invoiceFactory->create()->load($this->getInvoiceId()));
         }
         return $this->getData('invoice');