diff --git a/plugins/kernel_v2/config/vm_trigger.rb b/plugins/kernel_v2/config/vm_trigger.rb
index 5d7b3481b..9c45fbf8a 100644
--- a/plugins/kernel_v2/config/vm_trigger.rb
+++ b/plugins/kernel_v2/config/vm_trigger.rb
@@ -98,17 +98,19 @@ module VagrantPlugins
         # these values are expected to always be an Array internally,
         # but can be set as a single String or Symbol
         #
-        # map to all be strings
+        # Guests are stored internally as strings
         if !@only_on.nil?
           @only_on = Array(@only_on)
+          @only_on.map { |o| o.to_s }
         end
 
+        # Commands must be stored internally as symbols
         if !@ignore.nil?
-          @ignore = @ignore.to_sym if @ignore.is_a?(String)
           @ignore = Array(@ignore)
+          @ignore.map { |i| i.to_sym }
         end
 
-        # Convert @run and @run_remote to be a "Shell provisioner"
+        # Convert @run and @run_remote to be a "Shell provisioner" config
         if @run
           new_run = VagrantPlugins::Shell::Config.new()
           new_run.set_options(@run)