diff --git a/Rakefile b/Rakefile
index d37d4eb..a6a2291 100644
--- a/Rakefile
+++ b/Rakefile
@@ -39,8 +39,7 @@ end
 def coverage18(t)
   require 'rcov'
   t.rcov = true
-  rcov_helper =  File.expand_path(File.join(File.dirname(__FILE__), 'spec/rcov_helper.rb'))
-  t.rcov_opts = ["-Ispec:lib #{rcov_helper}", '--exclude', 'spec,teamcity/*,/usr/lib/ruby/,.gem/ruby,/boxgrinder-build/,/gems/']
+  t.rcov_opts = ["-Ispec:lib spec/rcov_helper.rb", '--exclude', 'spec,teamcity/*,/usr/lib/ruby/,.gem/ruby,/boxgrinder-build/,/gems/']
 end
 
 RSpec::Core::RakeTask.new('spec:coverage') do |t|