diff --git a/lib/vagrant/config/vm/provisioner.rb b/lib/vagrant/config/vm/provisioner.rb
index 9fc74bdab..48dce4435 100644
--- a/lib/vagrant/config/vm/provisioner.rb
+++ b/lib/vagrant/config/vm/provisioner.rb
@@ -9,7 +9,8 @@ module Vagrant
 
         def initialize(shortcut, options=nil, &block)
           @shortcut = shortcut
-          @provisioner = Provisioners::Base.registered[shortcut]
+          @provisioner = shortcut
+          @provisioner = Provisioners::Base.registered[shortcut] if shortcut.is_a?(Symbol)
           @config = nil
 
           configure(options, &block)
@@ -19,10 +20,10 @@ module Vagrant
         def configure(options=nil, &block)
           # We assume that every provisioner has a `Config` class beneath
           # it for configuring.
-          return if !defined?(@provisioner::Config)
+          return if !@provisioner || !@provisioner.const_defined?("Config", false)
 
           # Instantiate the config class and configure it
-          @config = @provisioner::Config.new
+          @config = @provisioner.const_get("Config", false).new
           block.call(@config) if block
 
           # TODO: Deal with the options hash
diff --git a/test/vagrant/config/vm/provisioner_test.rb b/test/vagrant/config/vm/provisioner_test.rb
new file mode 100644
index 000000000..38096ab0a
--- /dev/null
+++ b/test/vagrant/config/vm/provisioner_test.rb
@@ -0,0 +1,76 @@
+require "test_helper"
+
+class ConfigVMProvisionerTest < Test::Unit::TestCase
+  setup do
+    @klass = Vagrant::Config::VMConfig::Provisioner
+  end
+
+  context "initializing" do
+    should "expose the shortcut used" do
+      instance = @klass.new(:chef_solo)
+      assert_equal :chef_solo, instance.shortcut
+    end
+
+    should "expose the provisioner class if its a valid shortcut" do
+      instance = @klass.new(:chef_solo)
+      assert_equal Vagrant::Provisioners::ChefSolo, instance.provisioner
+    end
+
+    should "expose the provisioner class if its a valid class" do
+      instance = @klass.new(Vagrant::Provisioners::ChefSolo)
+      assert_equal Vagrant::Provisioners::ChefSolo, instance.provisioner
+    end
+
+    should "have a nil provisioner class if invalid" do
+      instance = @klass.new(:i_shall_never_exist)
+      assert_nil instance.provisioner
+    end
+
+    should "have a nil config instance if invalid" do
+      instance = @klass.new(:i_shall_never_exist)
+      assert_nil instance.config
+    end
+
+    should "configure the provisioner if valid" do
+      instance = @klass.new(:chef_solo) do |chef|
+        chef.cookbooks_path = "foo"
+      end
+
+      assert_equal "foo", instance.config.cookbooks_path
+    end
+  end
+
+  context "validation" do
+    setup do
+      @errors = Vagrant::Config::ErrorRecorder.new
+    end
+
+    should "be invalid if provisioner is valid" do
+      instance = @klass.new(:i_shall_never_exist)
+      instance.validate(@errors)
+      assert !@errors.errors.empty?
+    end
+
+    should "be invalid if provisioner doesn't inherit from provisioners base" do
+      klass = Class.new
+      instance = @klass.new(klass)
+      instance.validate(@errors)
+      assert !@errors.errors.empty?
+    end
+
+    should "be valid with a valid provisioner" do
+      instance = @klass.new(:chef_solo) do |chef|
+        chef.add_recipe "foo"
+      end
+
+      instance.validate(@errors)
+      assert @errors.errors.empty?
+    end
+
+    should "be invalid if a provisioner's config is invalid" do
+      instance = @klass.new(:chef_solo)
+      instance.validate(@errors)
+      assert !@errors.errors.empty?
+    end
+  end
+end