diff --git a/.travis.yml b/.travis.yml
index d5a8ebc32f1f..4bdcc265fb53 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -42,6 +42,7 @@ before_script:
   - cp tests/_bootstrap.php.default tests/_bootstrap.php
   - php artisan key:generate --no-interaction
   - sed -i 's/APP_ENV=production/APP_ENV=development/g' .env
+  - sed -i 's/APP_DEBUG=false/APP_DEBUG=true/g' .env
   # create the database and user
   - mysql -u root -e "create database IF NOT EXISTS ninja;"
   - mysql -u root -e "GRANT ALL PRIVILEGES ON ninja.* To 'ninja'@'localhost' IDENTIFIED BY 'ninja'; FLUSH PRIVILEGES;"
diff --git a/app/Http/Controllers/InvoiceApiController.php b/app/Http/Controllers/InvoiceApiController.php
index 8c4344f608b6..2ba39cd77651 100644
--- a/app/Http/Controllers/InvoiceApiController.php
+++ b/app/Http/Controllers/InvoiceApiController.php
@@ -280,7 +280,7 @@ class InvoiceApiController extends BaseAPIController
     private function prepareItem($item)
     {
         // if only the product key is set we'll load the cost and notes
-        if ($item['product_key'] && empty($item['cost']) && empty($item['notes'])) {
+        if (!empty($item['product_key']) && empty($item['cost']) && empty($item['notes'])) {
             $product = Product::findProductByKey($item['product_key']);
             if ($product) {
                 if (empty($item['cost'])) {