diff --git a/benchmark/fib.rb b/benchmark/bm_fib.rb
similarity index 100%
rename from benchmark/fib.rb
rename to benchmark/bm_fib.rb
diff --git a/tasks/benchmark.rake b/tasks/benchmark.rake
index 18802708e..3372c900a 100644
--- a/tasks/benchmark.rake
+++ b/tasks/benchmark.rake
@@ -5,7 +5,7 @@ end
 $dat_files = []
 
 def bm_files
-  Dir.glob("#{MRUBY_ROOT}/benchmark/*.rb")
+  Dir.glob("#{MRUBY_ROOT}/benchmark/bm_*.rb")
 end
 
 def plot_file