diff --git a/actionpack/Rakefile b/actionpack/Rakefile
index ba7956c3ab..875dfc69f2 100644
--- a/actionpack/Rakefile
+++ b/actionpack/Rakefile
@@ -22,11 +22,15 @@ Rake::TestTask.new(:test_action_pack) do |t|
 end
 
 namespace :test do
-  Rake::TestTask.new(:isolated) do |t|
-    t.libs << 'test'
-    t.pattern = 'test/ts_isolated.rb'
+  task :isolated do
+    ruby = File.join(*RbConfig::CONFIG.values_at('bindir', 'RUBY_INSTALL_NAME'))
+    Dir.glob("test/{abstract,controller,dispatch,template}/**/*_test.rb").all? do |file|
+      sh(ruby, '-Ilib:test', file)
+    end or raise "Failures"
   end
+end
 
+namespace :test do
   Rake::TestTask.new(:template) do |t|
     t.libs << 'test'
     t.pattern = 'test/template/**/*.rb'
diff --git a/actionpack/test/ts_isolated.rb b/actionpack/test/ts_isolated.rb
deleted file mode 100644
index 55620abe84..0000000000
--- a/actionpack/test/ts_isolated.rb
+++ /dev/null
@@ -1,15 +0,0 @@
-require 'active_support/testing/autorun'
-require 'rbconfig'
-require 'abstract_unit'
-
-class TestIsolated < ActiveSupport::TestCase
-  ruby = File.join(*RbConfig::CONFIG.values_at('bindir', 'RUBY_INSTALL_NAME'))
-
-  Dir["#{File.dirname(__FILE__)}/{abstract,controller,dispatch,template}/**/*_test.rb"].each do |file|
-    define_method("test #{file}") do
-      command = "#{ruby} -Ilib:test #{file}"
-      result = silence_stderr { `#{command}` }
-      assert $?.to_i.zero?, "#{command}\n#{result}"
-    end
-  end
-end
diff --git a/activesupport/Rakefile b/activesupport/Rakefile
index e3788ed54f..f50225a9f0 100644
--- a/activesupport/Rakefile
+++ b/activesupport/Rakefile
@@ -9,13 +9,16 @@ Rake::TestTask.new do |t|
   t.verbose = true
 end
 
+
 namespace :test do
-  Rake::TestTask.new(:isolated) do |t|
-    t.pattern = 'test/ts_isolated.rb'
+  task :isolated do
+    ruby = File.join(*RbConfig::CONFIG.values_at('bindir', 'RUBY_INSTALL_NAME'))
+    Dir.glob("test/**/*_test.rb").all? do |file|
+      sh(ruby, '-Ilib:test', file)
+    end or raise "Failures"
   end
 end
 
-
 spec = eval(File.read('activesupport.gemspec'))
 
 Gem::PackageTask.new(spec) do |p|
diff --git a/activesupport/test/ts_isolated.rb b/activesupport/test/ts_isolated.rb
deleted file mode 100644
index 294d6595f7..0000000000
--- a/activesupport/test/ts_isolated.rb
+++ /dev/null
@@ -1,16 +0,0 @@
-require 'active_support/testing/autorun'
-require 'active_support/test_case'
-require 'rbconfig'
-require 'active_support/core_ext/kernel/reporting'
-
-class TestIsolated < ActiveSupport::TestCase
-  ruby = File.join(*RbConfig::CONFIG.values_at('bindir', 'RUBY_INSTALL_NAME'))
-
-  Dir["#{File.dirname(__FILE__)}/**/*_test.rb"].each do |file|
-    define_method("test #{file}") do
-      command = "#{ruby} -Ilib:test #{file}"
-      result = silence_stderr { `#{command}` }
-      assert $?.to_i.zero?, "#{command}\n#{result}"
-    end
-  end
-end