diff --git a/lib/vagrant/action/builtin/wait_for_communicator.rb b/lib/vagrant/action/builtin/wait_for_communicator.rb
index <HASH>..<HASH> 100644
--- a/lib/vagrant/action/builtin/wait_for_communicator.rb
+++ b/lib/vagrant/action/builtin/wait_for_communicator.rb
@@ -52,6 +52,7 @@ module Vagrant
           # Wait for a result or an interrupt
           env[:ui].info I18n.t("vagrant.boot_waiting")
           while ready_thr.alive? && states_thr.alive?
+            sleep 1
             return if env[:interrupted]
           end
Sleep to avoid <I>% CPU in waiting time of 'vagrant up'