diff --git a/mrbgems/mruby-set/mrbgem.rake b/mrbgems/mruby-set/mrbgem.rake
index c59305709..5d6c77aa3 100644
--- a/mrbgems/mruby-set/mrbgem.rake
+++ b/mrbgems/mruby-set/mrbgem.rake
@@ -4,4 +4,5 @@ MRuby::Gem::Specification.new('mruby-set') do |spec|
 
   spec.add_dependency "mruby-hash-ext", :core => "mruby-hash-ext"
   spec.add_dependency "mruby-enumerator", :core => "mruby-enumerator"
+  spec.add_test_dependency "mruby-metaprog", :core => "mruby-metaprog"
 end