diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index 5f1be68..4f51fb0 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -3,7 +3,7 @@ require 'zero/all'
 class SpecApp
   attr_reader :env
 
-  def call(env)
+  def self.call(env)
     @env = env
     return [200, {'Content-Type' => 'text/html'}, ['success']]
   end