diff --git a/pkgs/mruby/build_config.rb b/pkgs/mruby/build_config.rb
index 2c4a639..a2ae5ef 100644
--- a/pkgs/mruby/build_config.rb
+++ b/pkgs/mruby/build_config.rb
@@ -2,5 +2,4 @@ MRuby::Build.new do |conf|
   conf.toolchain
   conf.enable_test
   conf.gem '.'
-  conf.gem core: 'mruby-bin-mirb'
 end