diff --git a/README.md b/README.md
index 8ca2766..2bf3cb5 100644
--- a/README.md
+++ b/README.md
@@ -14,6 +14,7 @@ Lots of fun options!
 * `:start_on_start` will start the server when starting Guard (default `true`)
 * `:force_run` kills any process that's holding open the listen port before attempting to (re)start Rails (default `false`).
 * `:daemon` runs the server as a daemon, without any output to the terminal that ran `guard` (default `false`).
+* `:debugger` runs the server with the debugger enabled (default `false`). Required ruby-debug gem.
 * `:timeout` waits this number of seconds when restarting the Rails server before reporting there's a problem (default `20`).
 * `:server` lets you specify the webserver engine to use (try `:server => :thin`).
 
diff --git a/lib/guard/rails.rb b/lib/guard/rails.rb
index fcdd3f4..fdcb2f2 100644
--- a/lib/guard/rails.rb
+++ b/lib/guard/rails.rb
@@ -13,7 +13,8 @@ module Guard
         :start_on_start => true,
         :force_run => false,
         :timeout => 20,
-        :server => nil
+        :server => nil,
+        :debugger => false
       }
 
     def initialize(watchers = [], options = {})
diff --git a/lib/guard/rails/runner.rb b/lib/guard/rails/runner.rb
index 322005c..dff1d80 100644
--- a/lib/guard/rails/runner.rb
+++ b/lib/guard/rails/runner.rb
@@ -23,7 +23,7 @@ module Guard
         FileUtils.rm pid_file
       end
     end
-    
+
     def restart
       stop
       start
@@ -37,6 +37,7 @@ module Guard
       ]
 
       rails_options << '-d' if options[:daemon]
+      rails_options << '-u' if options[:debugger]
       rails_options << options[:server] if options[:server]
 
       %{sh -c 'cd #{Dir.pwd} && rails s #{rails_options.join(' ')} &'}
diff --git a/spec/lib/guard/rails/runner_spec.rb b/spec/lib/guard/rails/runner_spec.rb
index e9f1c2a..182705c 100644
--- a/spec/lib/guard/rails/runner_spec.rb
+++ b/spec/lib/guard/rails/runner_spec.rb
@@ -47,6 +47,14 @@ describe Guard::RailsRunner do
         runner.build_rails_command.should match(%r{ -d})
       end
     end
+    
+    context 'debugger' do
+      let(:options) { default_options.merge(:debugger => true) }
+
+      it "should have a debugger switch" do
+        runner.build_rails_command.should match(%r{ -u})
+      end
+    end
 
     context 'custom server' do
       let(:options) { default_options.merge(:server => 'thin') }