diff --git a/test/test_app.rb b/test/test_app.rb
index c0f66820..afee0aad 100644
--- a/test/test_app.rb
+++ b/test/test_app.rb
@@ -52,6 +52,7 @@ context "Frontend" do
 
   test "previews content" do
     post "/preview", :content => 'abc', :format => 'markdown'
+    assert last_response.ok?
   end
 
   def app