diff --git a/lib/vagrant/plugin/v2/plugin.rb b/lib/vagrant/plugin/v2/plugin.rb
index 72fa95e58..eb8ee7a1b 100644
--- a/lib/vagrant/plugin/v2/plugin.rb
+++ b/lib/vagrant/plugin/v2/plugin.rb
@@ -289,7 +289,7 @@ module Vagrant
         protected
 
         # Sentinel value denoting that a value has not been set.
-        UNSET_VALUE = Object.new
+        UNSET_VALUE = :__UNSET__VALUE__
 
         # Helper method that will set a value if a value is given, or otherwise
         # return the already set value.