diff --git a/lib/validates_timeliness/conversion.rb b/lib/validates_timeliness/conversion.rb
index 81d8468..7bd26d0 100644
--- a/lib/validates_timeliness/conversion.rb
+++ b/lib/validates_timeliness/conversion.rb
@@ -56,6 +56,7 @@ module ValidatesTimeliness
     end
 
     def parse(value)
+      return nil if value.nil?
       if ValidatesTimeliness.use_plugin_parser
         Timeliness::Parser.parse(value, @type, :zone => (:current if @timezone_aware), :format => options[:format], :strict => false)
       else
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index 9efd455..9417565 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -11,6 +11,7 @@ require 'validates_timeliness'
 
 require 'support/test_model'
 require 'support/model_helpers'
+require 'support/config_helper'
 
 ValidatesTimeliness.setup do |c|
   c.extend_orms = [ :active_record ]
@@ -89,6 +90,7 @@ Rspec.configure do |c|
   c.mock_with :rspec
   c.include(RspecTagMatchers)
   c.include(ModelHelpers)
+  c.include(ConfigHelper)
   c.before do
     Person.reset_callbacks(:validate)
     PersonWithShim.timeliness_validated_attributes = []
diff --git a/spec/support/config_helper.rb b/spec/support/config_helper.rb
new file mode 100644
index 0000000..329a1f1
--- /dev/null
+++ b/spec/support/config_helper.rb
@@ -0,0 +1,10 @@
+module ConfigHelper
+  # Justin French tip
+  def with_config(preference_name, temporary_value)
+    old_value = ValidatesTimeliness.send(preference_name)
+    ValidatesTimeliness.send(:"#{preference_name}=", temporary_value)
+    yield
+  ensure
+    ValidatesTimeliness.send(:"#{preference_name}=", old_value)
+  end
+end
diff --git a/spec/validates_timeliness/conversion_spec.rb b/spec/validates_timeliness/conversion_spec.rb
index 656ff57..a113e87 100644
--- a/spec/validates_timeliness/conversion_spec.rb
+++ b/spec/validates_timeliness/conversion_spec.rb
@@ -3,13 +3,13 @@ require 'spec_helper'
 describe ValidatesTimeliness::Conversion do
   include ValidatesTimeliness::Conversion
 
+  let(:options) { Hash.new }
+
   before do
     Timecop.freeze(Time.mktime(2010, 1, 1, 0, 0, 0))
   end
 
   describe "#type_cast_value" do
-    let(:options) { Hash.new }
-
     describe "for date type" do
       it "should return same value for date value" do
         type_cast_value(Date.new(2010, 1, 1), :date).should == Date.new(2010, 1, 1)
@@ -206,4 +206,40 @@ describe ValidatesTimeliness::Conversion do
       end
     end
   end
+
+  describe "#parse" do
+    context "use_plugin_parser setting is true" do
+      around do |example|
+        with_config(:use_plugin_parser, true, &example)
+      end
+
+      it 'should use timeliness' do
+        Timeliness::Parser.should_receive(:parse)
+        parse('2000-01-01')
+      end
+    end
+
+    context "use_plugin_parser setting is false" do
+      around do |example|
+        with_config(:use_plugin_parser, false, &example)
+      end
+
+      it 'should use Time.zone.parse attribute is timezone aware' do
+        @timezone_aware = true
+        Time.zone.should_receive(:parse)
+        parse('2000-01-01')
+      end
+
+      it 'should use value#to_time if use_plugin_parser setting is false and attribute is not timezone aware' do
+        @timezone_aware = false
+        value = '2000-01-01'
+        value.should_receive(:to_time)
+        parse(value)
+      end
+    end
+
+    it 'should return nil if value is nil' do
+      parse(nil).should be_nil
+    end
+  end
 end