diff --git a/mrbgem.rake b/mrbgem.rake
index 1b78ba9bb..f57d8ade8 100644
--- a/mrbgem.rake
+++ b/mrbgem.rake
@@ -1,4 +1,8 @@
 MRuby::Gem::Specification.new('mruby-set') do |spec|
   spec.license = 'MIT'
   spec.authors = 'yui-knk'
+
+  spec.add_dependency "mruby-sprintf", :core => "mruby-sprintf"
+  spec.add_dependency "mruby-hash-ext", :core => "mruby-hash-ext"
+  spec.add_dependency "mruby-enumerator", :core => "mruby-enumerator"
 end