diff --git a/mrbgems/mruby-bin-debugger/mrbgem.rake b/mrbgems/mruby-bin-debugger/mrbgem.rake
index f51c9a3db..3372950c5 100644
--- a/mrbgems/mruby-bin-debugger/mrbgem.rake
+++ b/mrbgems/mruby-bin-debugger/mrbgem.rake
@@ -4,6 +4,7 @@ MRuby::Gem::Specification.new('mruby-bin-debugger') do |spec|
   spec.summary = 'mruby debugger command'
   spec.build.defines << "MRB_USE_DEBUG_HOOK"
   spec.add_dependency('mruby-eval', :core => 'mruby-eval')
+  spec.add_test_dependency('mruby-bin-mrbc', :core => 'mruby-bin-mrbc')
 
   spec.bins = %w(mrdb)
 end