diff --git a/Library/Homebrew/dev-cmd/test-bot.rb b/Library/Homebrew/dev-cmd/test-bot.rb
index 3c784d8dfc..7fac2c9a99 100644
--- a/Library/Homebrew/dev-cmd/test-bot.rb
+++ b/Library/Homebrew/dev-cmd/test-bot.rb
@@ -876,6 +876,7 @@ module Homebrew
 
     ENV["HOMEBREW_DEVELOPER"] = "1"
     ENV["HOMEBREW_SANDBOX"] = "1"
+    ENV["HOMEBREW_RUBY_MACHO"] = "1" if RUBY_VERSION.split(".").first.to_i >= 2
     ENV["HOMEBREW_NO_EMOJI"] = "1"
     ENV["HOMEBREW_FAIL_LOG_LINES"] = "150"
     ENV["HOMEBREW_EXPERIMENTAL_FILTER_FLAGS_ON_DEPS"] = "1"