diff --git a/activesupport/lib/active_support/core_ext/benchmark.rb b/activesupport/lib/active_support/core_ext/benchmark.rb
index 98e61e646a..79ba165e3a 100644
--- a/activesupport/lib/active_support/core_ext/benchmark.rb
+++ b/activesupport/lib/active_support/core_ext/benchmark.rb
@@ -1,12 +1,12 @@
 require 'benchmark'
 
-module Benchmark
+class << Benchmark
   remove_method :realtime
+
   def realtime
     r0 = Time.now
     yield
     r1 = Time.now
     r1.to_f - r0.to_f
   end
-  module_function :realtime
-end
\ No newline at end of file
+end