diff --git a/lib/tasks/rspec.rake b/lib/tasks/rspec.rake
--- a/lib/tasks/rspec.rake
+++ b/lib/tasks/rspec.rake
@@ -1,7 +1,7 @@
-gem 'test-unit', '1.2.3' if RUBY_VERSION.to_f >= 1.9
+gem 'test-unit' if RUBY_VERSION.to_f >= 1.9
 rspec_gem_dir = nil
-Dir["#{RAILS_ROOT}/vendor/gems/*"].each do |subdir|
-  rspec_gem_dir = subdir if subdir.gsub("#{RAILS_ROOT}/vendor/gems/","") =~ /^(\w+-)?rspec-(\d+)/ && File.exist?("#{subdir}/lib/spec/rake/spectask.rb")
+Dir["#{Rails.root}/vendor/gems/*"].each do |subdir|
+  rspec_gem_dir = subdir if subdir.gsub("#{Rails.root}/vendor/gems/","") =~ /^(\w+-)?rspec-(\d+)/ && File.exist?("#{subdir}/lib/spec/rake/spectask.rb")
 end
 rspec_plugin_dir = File.expand_path(File.dirname(__FILE__) + '/../../vendor/plugins/rspec')
 
@@ -47,7 +47,7 @@
 
 Rake.application.instance_variable_get('@tasks').delete('default')
 
-spec_prereq = File.exist?(File.join(RAILS_ROOT, 'config', 'database.yml')) ? "db:test:prepare" : :noop
+spec_prereq = File.exist?(File.join(Rails.root, 'config', 'database.yml')) ? "db:test:prepare" : :noop
 task :noop do
 end
 
@@ -56,18 +56,18 @@
 
 desc "Run all specs in spec directory (excluding plugin specs)"
 Spec::Rake::SpecTask.new(:spec => spec_prereq) do |t|
-  t.spec_opts = ['--options', "\"#{RAILS_ROOT}/spec/spec.opts\""]
+  t.spec_opts = ['--options', "\"#{Rails.root}/spec/spec.opts\""]
   t.spec_files = FileList['spec/**/*_spec.rb']
 end
 
 namespace :spec do
   desc "Run all specs in spec directory with RCov (excluding plugin specs)"
   Spec::Rake::SpecTask.new(:rcov) do |t|
-    t.spec_opts = ['--options', "\"#{RAILS_ROOT}/spec/spec.opts\""]
+    t.spec_opts = ['--options', "\"#{Rails.root}/spec/spec.opts\""]
     t.spec_files = FileList['spec/**/*_spec.rb']
     t.rcov = true
     t.rcov_opts = lambda do
-      IO.readlines("#{RAILS_ROOT}/spec/rcov.opts").map {|l| l.chomp.split " "}.flatten
+      IO.readlines("#{Rails.root}/spec/rcov.opts").map {|l| l.chomp.split " "}.flatten
     end
   end
 
@@ -86,21 +86,21 @@
   [:models, :controllers, :views, :helpers, :lib, :integration].each do |sub|
     desc "Run the code examples in spec/#{sub}"
     Spec::Rake::SpecTask.new(sub => spec_prereq) do |t|
-      t.spec_opts = ['--options', "\"#{RAILS_ROOT}/spec/spec.opts\""]
+      t.spec_opts = ['--options', "\"#{Rails.root}/spec/spec.opts\""]
       t.spec_files = FileList["spec/#{sub}/**/*_spec.rb"]
     end
   end
 
   desc "Run the code examples in vendor/plugins (except RSpec's own)"
   Spec::Rake::SpecTask.new(:plugins => spec_prereq) do |t|
-    t.spec_opts = ['--options', "\"#{RAILS_ROOT}/spec/spec.opts\""]
+    t.spec_opts = ['--options', "\"#{Rails.root}/spec/spec.opts\""]
     t.spec_files = FileList['vendor/plugins/**/spec/**/*_spec.rb'].exclude('vendor/plugins/rspec/*').exclude("vendor/plugins/rspec-rails/*")
   end
 
   namespace :plugins do
     desc "Runs the examples for rspec_on_rails"
     Spec::Rake::SpecTask.new(:rspec_on_rails) do |t|
-      t.spec_opts = ['--options', "\"#{RAILS_ROOT}/spec/spec.opts\""]
+      t.spec_opts = ['--options', "\"#{Rails.root}/spec/spec.opts\""]
       t.spec_files = FileList['vendor/plugins/rspec-rails/spec/**/*_spec.rb']
     end
   end