diff --git a/lib/mruby/presym.rb b/lib/mruby/presym.rb
index 0009c9684..6a68cf65c 100644
--- a/lib/mruby/presym.rb
+++ b/lib/mruby/presym.rb
@@ -1,7 +1,5 @@
 module MRuby
   class Presym
-    include Rake::DSL
-
     OPERATORS = {
       "!" => "not",
       "%" => "mod",