diff --git a/lib/jsonapi/resources/matchers/integrations/rspec.rb b/lib/jsonapi/resources/matchers/integrations/rspec.rb
index 98316fd..78fd3e2 100644
--- a/lib/jsonapi/resources/matchers/integrations/rspec.rb
+++ b/lib/jsonapi/resources/matchers/integrations/rspec.rb
@@ -1,4 +1,5 @@
 if defined?(RSpec)
+  require 'rspec/core'
   RSpec.configure do |c|
     c.include JSONAPI::Resources::Matchers, type: :resource
   end