diff --git a/activesupport/lib/active_support/testing/performance.rb b/activesupport/lib/active_support/testing/performance.rb
index bd136c25966afb9e8d9d21887472ed2e90a8d80b..f8d12e82b346f4d00ab08785304f13b0881e5f93 100644
--- a/activesupport/lib/active_support/testing/performance.rb
+++ b/activesupport/lib/active_support/testing/performance.rb
@@ -12,7 +12,7 @@ module Performance
         if benchmark = ARGV.include?('--benchmark')  # HAX for rake test
           { :benchmark => true,
             :runs => 4,
-            :metrics => [:process_time, :memory, :objects, :gc_runs, :gc_time],
+            :metrics => [:wall_time, :memory, :objects, :gc_runs, :gc_time],
             :output => 'tmp/performance' }
         else
           { :benchmark => false,