diff --git a/Gemfile b/Gemfile
index ef38693380..1afbf36f3a 100644
--- a/Gemfile
+++ b/Gemfile
@@ -2,4 +2,4 @@ source "http://rubygems.org"
 gemspec
 
 gem "ruby-debug",   :platforms => :mri_18
-gem "ruby-debug19", :platforms => :mri_19, :require => 'ruby-debug'
+gem "ruby-debug19", :platforms => :mri_19, :require => 'ruby-debug' if RUBY_VERSION < "1.9.3"