diff --git a/tasks/benchmark.rake b/tasks/benchmark.rake
index 5c69f3c0f..78240c1d6 100644
--- a/tasks/benchmark.rake
+++ b/tasks/benchmark.rake
@@ -1,65 +1,70 @@
 require 'benchmark'
 require 'tmpdir'
 
 namespace :benchmark do
   def generate_scenario_tasks(location, name)
     desc File.read(File.join(location, 'description'))
     task name => "#{name}:run"
 
     namespace name do
       task :setup do
         ENV['ITERATIONS'] ||= '10'
         ENV['SIZE'] ||= '100'
         ENV['TARGET'] ||= Dir.mktmpdir(name)
         ENV['TARGET'] = File.expand_path(ENV['TARGET'])
 
         mkdir_p(ENV['TARGET'])
 
         require File.expand_path(File.join(location, 'benchmarker.rb'))
 
         @benchmark = Benchmarker.new(ENV['TARGET'], ENV['SIZE'].to_i)
       end
 
       desc "Generate the #{name} scenario."
       task :generate => :setup do
         @benchmark.generate
       end
 
       desc "Run the #{name} scenario."
       task :run => :generate do
+        format = if RUBY_VERSION =~ /^1\.8/
+                   Benchmark::FMTSTR
+                 else
+                   Benchmark::FORMAT
+                 end
         @benchmark.setup
-        Benchmark.benchmark(Benchmark::CAPTION, 10, Benchmark::FORMAT, "> total:", "> avg:") do |b|
+        Benchmark.benchmark(Benchmark::CAPTION, 10, format, "> total:", "> avg:") do |b|
           times = []
           ENV['ITERATIONS'].to_i.times do |i|
             times << b.report("Run #{i + 1}") do
               @benchmark.run
             end
           end
 
           sum = times.inject(Benchmark::Tms.new, &:+)
 
           [sum, sum / times.length]
         end
       end
 
       desc "Profile a single run of the #{name} scenario."
       task :profile => :generate do
         require 'ruby-prof'
 
         @benchmark.setup
         result = RubyProf.profile do
           @benchmark.run
         end
 
         printer = RubyProf::CallTreePrinter.new(result)
         File.open(File.join("callgrind.#{name}.#{Time.now.to_i}.trace"), "w") do |f|
           printer.print(f)
         end
       end
     end
   end
 
   Dir.glob('benchmarks/*') do |location|
     generate_scenario_tasks(location, File.basename(location))
   end
 end