diff --git a/plugins/provisioners/shell/config.rb b/plugins/provisioners/shell/config.rb
index c0b0b7cf2..2c98468b2 100644
--- a/plugins/provisioners/shell/config.rb
+++ b/plugins/provisioners/shell/config.rb
@@ -29,6 +29,10 @@ module VagrantPlugins
         @privileged  = true if @privileged == UNSET_VALUE
         @binary      = false if @binary == UNSET_VALUE
         @keep_color  = false if @keep_color == UNSET_VALUE
+
+        if @args && !@args.is_a?(Array) && args_valid?
+          @args = @args.to_s
+        end
       end
 
       def validate(machine)
@@ -66,11 +70,13 @@ module VagrantPlugins
       # string or as an array.
       def args_valid?
         return true if !args
-        return true if args.is_a?(String) or args.is_a?(Fixnum)
+        return true if args.is_a?(String)
+        return true if args.is_a?(Fixnum)
         if args.is_a?(Array)
           args.each do |a|
-            return false if not a.kind_of?(String) and not a.kind_of?(Fixnum)
+            return false if !a.kind_of?(String) && !a.kind_of?(Fixnum)
           end
+
           return true
         end
       end
diff --git a/plugins/provisioners/shell/provisioner.rb b/plugins/provisioners/shell/provisioner.rb
index 04ee3c8ef..3eb442d18 100644
--- a/plugins/provisioners/shell/provisioner.rb
+++ b/plugins/provisioners/shell/provisioner.rb
@@ -8,10 +8,10 @@ module VagrantPlugins
     class Provisioner < Vagrant.plugin("2", :provisioner)
       def provision
         args = ""
-        if config.args.is_a?(String) or config.args.is_a?(Fixnum)
+        if config.args.is_a?(String)
           args = " #{config.args.to_s}"
         elsif config.args.is_a?(Array)
-          args = config.args.map { |a| quote_and_escape(a.to_s) }
+          args = config.args.map { |a| quote_and_escape(a) }
           args = " #{args.join(" ")}"
         end