diff --git a/lib/whenever/capistrano.rb b/lib/whenever/capistrano.rb
index 7342abf..0c263d2 100644
--- a/lib/whenever/capistrano.rb
+++ b/lib/whenever/capistrano.rb
@@ -1,32 +1,62 @@
 Capistrano::Configuration.instance(:must_exist).load do
-  
   _cset(:whenever_roles)        { :db }
   _cset(:whenever_command)      { "whenever" }
-  _cset(:whenever_identifier)   { application }
-  _cset(:whenever_environment)  { "production" }
-  _cset(:whenever_update_flags) { "--update-crontab #{whenever_identifier} --set environment=#{whenever_environment}" }
-  _cset(:whenever_clear_flags)  { "--clear-crontab #{whenever_identifier}" }
-  
+  _cset(:whenever_identifier)   { fetch :application }
+  _cset(:whenever_environment)  { fetch :rails_env, "production" }
+  _cset(:whenever_update_flags) { "--update-crontab #{fetch :whenever_identifier} --set environment=#{fetch :whenever_environment}" }
+  _cset(:whenever_clear_flags)  { "--clear-crontab #{fetch :whenever_identifier}" }
+
   # Disable cron jobs at the begining of a deploy.
   after "deploy:update_code", "whenever:clear_crontab"
   # Write the new cron jobs near the end.
   after "deploy:symlink", "whenever:update_crontab"
   # If anything goes wrong, undo.
   after "deploy:rollback", "whenever:update_crontab"
-  
+
   namespace :whenever do
-    desc "Update application's crontab entries using Whenever"
-    task :update_crontab, :roles => whenever_roles do
-      # Hack by Jamis to skip a task if the role has no servers defined. http://tinyurl.com/ckjgnz
-      next if find_servers_for_task(current_task).empty?
-      run "cd #{current_path} && #{whenever_command} #{whenever_update_flags}"
+    desc <<-DESC
+      Update application's crontab entries using Whenever. You can configure \
+      the command used to invoke Whenever by setting the :whenever_command \
+      variable, which can be used with Bundler to set the command to \
+      "bundle exec whenever". You can configure the identifier used by setting \
+      the :whenever_identifier variable, which defaults to the same value configured \
+      for the :application variable. You can configure the environment by setting \
+      the :whenever_environment variable, which defaults to the same value \
+      configured for the :rails_env variable which itself defaults to "production". \
+      Finally, you can completely override all arguments to the Whenever command \
+      by setting the :whenever_update_flags variable. Additionally you can configure \
+      which servers the crontab is updated on by setting the :whenever_roles variable.
+    DESC
+    task :update_crontab do
+      options = { :roles => fetch(:whenever_roles) }
+
+      if find_servers(options).any?
+        on_rollback do
+          if fetch :previous_release
+            run "cd #{fetch :previous_release} && #{fetch :whenever_command} #{fetch :whenever_update_flags}", options
+          else
+            run "cd #{fetch :release_path} && #{fetch :whenever_command} #{fetch :whenever_clear_flags}", options
+          end
+        end
+
+        run "cd #{fetch :current_path} && #{fetch :whenever_command} #{fetch :whenever_update_flags}", options
+      end
     end
 
-    desc "Clear application's crontab entries using Whenever"
-    task :clear_crontab, :roles => whenever_roles do
-      next if find_servers_for_task(current_task).empty?
-      run "cd #{release_path} && #{whenever_command} #{whenever_clear_flags}"
+    desc <<-DESC
+      Clear application's crontab entries using Whenever. You can configure \
+      the command used to invoke Whenever by setting the :whenever_command \
+      variable, which can be used with Bundler to set the command to \
+      "bundle exec whenever". You can configure the identifier used by setting \
+      the :whenever_identifier variable, which defaults to the same value configured \
+      for the :application variable. Finally, you can completely override all \
+      arguments to the Whenever command by setting the :whenever_clear_flags variable. \
+      Additionally you can configure which servers the crontab is cleared on by setting \
+      the :whenever_roles variable.
+    DESC
+    task :clear_crontab do
+      options = { :roles => whenever_roles }
+      run "cd #{fetch :release_path} && #{fetch :whenever_command} #{fetch :whenever_clear_flags}", options if find_servers(options).any?
     end
   end
-  
-end
\ No newline at end of file
+end