diff --git a/spec/support/mock_parser.rb b/spec/support/mock_parser.rb
index d9a78961..6877df0a 100644
--- a/spec/support/mock_parser.rb
+++ b/spec/support/mock_parser.rb
@@ -1,5 +1,7 @@
 # frozen_string_literal: true
 
+require 'ostruct'
+
 module GrapeSwagger
   class MockParser
     attr_reader :model, :endpoint