diff --git a/.rubocop_todo.yml b/.rubocop_todo.yml
index 39152e6..c1363c5 100644
--- a/.rubocop_todo.yml
+++ b/.rubocop_todo.yml
@@ -108,6 +108,7 @@ Style/ClassVars:
   Exclude:
     - 'test/emails_test.rb'
     - 'test/files_test.rb'
+    - 'test/previews_test.rb'
     - 'test/mailer.rb'
 
 # Offense count: 28
diff --git a/lib/Mailosaur/models/preview_request.rb b/lib/Mailosaur/models/preview_request.rb
index 662bbd0..5542339 100644
--- a/lib/Mailosaur/models/preview_request.rb
+++ b/lib/Mailosaur/models/preview_request.rb
@@ -1,7 +1,7 @@
 module Mailosaur
   module Models
     class PreviewRequest < BaseModel
-      def initialize(email_client, disable_images = false)
+      def initialize(email_client, disable_images: false)
         @email_client = email_client
         @disable_images = disable_images
       end
diff --git a/test/previews_test.rb b/test/previews_test.rb
index f178b98..fdad690 100644
--- a/test/previews_test.rb
+++ b/test/previews_test.rb
@@ -44,7 +44,7 @@ def startup
 
         result = @@client.messages.generate_previews(email.id, options)
 
-        assert_true(result.items.length > 0)
+        assert_false(result.items.empty)
 
         # Ensure we can download one of the generated preview
         file = @@client.files.get_preview(result.items[0].id)