diff --git a/lib/vagrant-hostmanager/hosts_file.rb b/lib/vagrant-hostmanager/hosts_file.rb
index 582ba53..703e7db 100644
--- a/lib/vagrant-hostmanager/hosts_file.rb
+++ b/lib/vagrant-hostmanager/hosts_file.rb
@@ -80,7 +80,9 @@ module VagrantPlugins
         ip = get_ip_address(machine, resolving_machine)
         host = machine.config.vm.hostname || machine.name
         aliases = machine.config.hostmanager.aliases.join(' ').chomp
-        "#{ip}\t#{host} #{aliases}\n"
+        if ip != nil
+          "#{ip}\t#{host} #{aliases}\n"
+        end
       end
 
       def get_ip_address(machine, resolving_machine)
diff --git a/test/Vagrantfile b/test/Vagrantfile
index 24683e6..59ca656 100644
--- a/test/Vagrantfile
+++ b/test/Vagrantfile
@@ -33,4 +33,9 @@ Vagrant.configure('2') do |config|
     server.vm.network :private_network, :ip => '10.0.5.4'
     server.vm.provision :hostmanager
   end
-end
\ No newline at end of file
+
+  config.vm.define :server4 do |server|
+    server.vm.hostname = 'scruffy'
+    server.vm.provision :hostmanager
+  end
+end