diff --git a/lib/debug.rb b/lib/debug.rb
index 15ebccb62..a4890123a 100644
--- a/lib/debug.rb
+++ b/lib/debug.rb
@@ -1,5 +1,9 @@
 # frozen_string_literal: true
 
-require_relative 'debug/session'
-return unless defined?(DEBUGGER__)
-DEBUGGER__::start no_sigint_hook: true, nonstop: true
+if ENV['RUBY_DEBUG_LAZY']
+  require_relative 'debug/prelude'
+else
+  require_relative 'debug/session'
+  return unless defined?(DEBUGGER__)
+  DEBUGGER__::start no_sigint_hook: true, nonstop: true
+end