diff --git a/README.md b/README.md
index df796956..da072a3d 100644
--- a/README.md
+++ b/README.md
@@ -67,7 +67,6 @@ You can run tests both with
 
 * `rake test` or just `rake`
 * run any test file directly, e.g. `ruby -Ilib -Itest test/api/simple_test.rb`
-* run all tests with `ruby -Ilib -Itest test/all.rb`
 
 You can run all tests against all Gemfiles with
 
diff --git a/test/run_all.rb b/test/run_all.rb
index 46bc43c3..64ff743d 100644
--- a/test/run_all.rb
+++ b/test/run_all.rb
@@ -14,7 +14,7 @@ def execute(command)
   ENV['BUNDLE_GEMFILE'] = File.expand_path("../../#{gemfile}", __FILE__)
 
   execute 'bundle install' unless bundle_check
-  execute 'bundle exec ruby -w -Ilib -Itest test/all.rb'
+  execute 'bundle exec rake test'
 end
 
 exit results.all?