diff --git a/lib/statsample.rb b/lib/statsample.rb
index ce5cc8b..3fe7a0f 100644
--- a/lib/statsample.rb
+++ b/lib/statsample.rb
@@ -54,10 +54,6 @@ def include_aliasing(m, suffix = 'ruby')
 end
 
 class Array
-  def sum
-    inject(:+)
-  end
-
   def mean
     sum.fdiv(size)
   end