diff --git a/spec/mask_validator_spec.rb b/spec/mask_validator_spec.rb
index 32cbe3d..0cd6789 100644
--- a/spec/mask_validator_spec.rb
+++ b/spec/mask_validator_spec.rb
@@ -2,42 +2,28 @@
 
 describe MaskValidator do
   subject do
-    Person.new :phone => '(12) 3456-7890',
-               :fax => '(12) 3456-7890',
-               :acronym => 'ABC',
-               :alphanumeric => 'AAA666',
-               :zip_code => '88900-000',
-               :birth_date => '13/10/1989',
-               :birth_time => '10:20',
-               :birth_year => '2011',
-               :body_fat => '23,44',
-               :custom => '989.78',
-               :identification => '53.86'
-  end
-
-  it "Person should be valid" do
-    subject.should be_valid
+    Person.new
   end
 
   # validates :phone, :mask => "(99) 9999-9999", :allow_blank => true
   context "mask validation to phone" do
     it "should be valid with a phone in according of the mask" do
       subject.phone = '(48) 9874-4569'
-      subject.should be_valid
+      subject.should have_valid_value_to(:phone)
     end
 
     it "should not be valid with a phone with a wrong pattern" do
       subject.phone = '4852458787'
-      subject.should_not be_valid
+      subject.should_not have_valid_value_to(:phone)
 
       subject.phone = '48 9865 4879'
-      subject.should_not be_valid
+      subject.should_not have_valid_value_to(:phone)
 
       subject.phone = '(48) 9874-45169'
-      subject.should_not be_valid
+      subject.should_not have_valid_value_to(:phone)
 
       subject.phone = '(48)98956698'
-      subject.should_not be_valid
+      subject.should_not have_valid_value_to(:phone)
     end
   end
 
@@ -45,18 +31,18 @@
   context "mask validation to acronym" do
     it "should be valid with a acronym in according of the mask" do
       subject.acronym = '1gd'
-      subject.should be_valid
+      subject.should have_valid_value_to(:acronym)
 
       subject.acronym = '666'
-      subject.should be_valid
+      subject.should have_valid_value_to(:acronym)
 
       subject.acronym = 'zzz'
-      subject.should be_valid
+      subject.should have_valid_value_to(:acronym)
     end
 
     it "should not be valid with a acronym with a wrong pattern" do
       subject.acronym = '1qw1'
-      subject.should_not be_valid
+      subject.should_not have_valid_value_to(:acronym)
     end
   end
 
@@ -64,43 +50,43 @@
   context "mask validation to alphanumeric" do
     it "should be valid with a alphanumeric in according of the mask" do
       subject.alphanumeric = 'awe987'
-      subject.should be_valid
+      subject.should have_valid_value_to(:alphanumeric)
     end
 
     it "should not be valid with a alphanumeric with a wrong pattern" do
       subject.alphanumeric = '999999'
-      subject.should_not be_valid
+      subject.should_not have_valid_value_to(:alphanumeric)
 
       subject.alphanumeric = 'QQQQQQ'
-      subject.should_not be_valid
+      subject.should_not have_valid_value_to(:alphanumeric)
 
       subject.alphanumeric = '666aaaa'
-      subject.should_not be_valid
+      subject.should_not have_valid_value_to(:alphanumeric)
 
       subject.alphanumeric = '666AAA'
-      subject.should_not be_valid
+      subject.should_not have_valid_value_to(:alphanumeric)
     end
   end
 
   context "when the attributes type is not a string" do
     it "should not be valid with a wrong date format" do
       subject.birth_date = "15-12-2009"
-      subject.should be_invalid
+      subject.should_not have_valid_value_to(:birth_date)
     end
 
     it "should not be valid with a wrong birth year" do
       subject.birth_year = 20110
-      subject.should be_invalid
+      subject.should_not have_valid_value_to(:birth_year)
     end
 
     it "should not be valid with a wrong birth time" do
       subject.birth_time = "333:20"
-      subject.should be_invalid
+      subject.should_not have_valid_value_to(:birth_time)
     end
 
     it "should not be valid with a wrong body fat" do
       subject.body_fat = 333.00
-      subject.should be_invalid
+      subject.should_not have_valid_value_to(:body_fat)
     end
   end
 
@@ -109,13 +95,13 @@
     it "should be valid with an correct custom value" do
       subject.stub!(:custom_mask => "99999-999")
       subject.custom = '32632-567'
-      subject.should be_valid
+      subject.should have_valid_value_to(:custom)
     end
 
     it "should not be valid with an empty custom value" do
       subject.stub!(:custom_mask => "9.9.9")
       subject.custom = ''
-      subject.should_not be_valid
+      subject.should_not have_valid_value_to(:custom)
     end
   end
 
@@ -124,13 +110,13 @@
     it "should be valid with an correct value" do
       subject.stub!(:proc_mask => "999.9.99")
       subject.identification = '326.3.67'
-      subject.should be_valid
+      subject.should have_valid_value_to(:identification)
     end
 
     it "should not be valid with an empty value" do
       subject.stub!(:prock_mask => "9.9.9")
       subject.identification = ''
-      subject.should_not be_valid
+      subject.should_not have_valid_value_to(:identification)
     end
   end
 
@@ -138,12 +124,12 @@
   context "mask validation to phone with explicit ':allow_blank => true'" do
     it "should not be valid with an nil phone" do
       subject.phone = nil
-      subject.should be_valid
+      subject.should have_valid_value_to(:phone)
     end
 
     it "should be valid with an empty phone" do
       subject.phone = ''
-      subject.should be_valid
+      subject.should have_valid_value_to(:phone)
     end
   end
 
@@ -151,12 +137,12 @@
   context "mask validation to acronym with explicit ':allow_nil => true'" do
     it "should be valid with an nil acronym" do
       subject.acronym = nil
-      subject.should be_valid
+      subject.should have_valid_value_to(:acronym)
     end
 
     it "should be valid with an empty acronym" do
       subject.acronym = ''
-      subject.should be_invalid
+      subject.should_not have_valid_value_to(:acronym)
     end
   end
 
@@ -164,12 +150,12 @@
   context "mask validation to fax with explicit ':allow_nil => false'" do
     it "should not be valid with an nil fax" do
       subject.fax = nil
-      subject.should be_invalid
+      subject.should_not have_valid_value_to(:fax)
     end
 
     it "should be valid with an empty fax" do
       subject.fax = ''
-      subject.should be_invalid
+      subject.should_not have_valid_value_to(:fax)
     end
   end
 
@@ -177,12 +163,12 @@
   context "mask validation to zip_code with explicit ':allow_blank => false'" do
     it "should not be valid with an nil zip_code" do
       subject.zip_code = nil
-      subject.should be_invalid
+      subject.should_not have_valid_value_to(:zip_code)
     end
 
     it "should be valid with an empty zip_code" do
       subject.zip_code = ''
-      subject.should be_invalid
+      subject.should_not have_valid_value_to(:zip_code)
     end
   end
 
@@ -190,12 +176,12 @@
   context "mask validation to birth_date with implicit ':allow_blank => false'" do
     it "should not be valid with an nil birth_date" do
       subject.birth_date = nil
-      subject.should be_invalid
+      subject.should_not have_valid_value_to(:birth_date)
     end
 
     it "should be valid with an empty birth_date" do
       subject.birth_date = ''
-      subject.should be_invalid
+      subject.should_not have_valid_value_to(:birth_date)
     end
   end
 end
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index 4b298f1..05ed387 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -5,3 +5,19 @@
 
 require "support/db/schema"
 require "support/models/person"
+
+RSpec::Matchers.define :have_valid_value_to do |attribute|
+  match do |actual|
+    actual.valid?
+
+    !actual.errors[attribute].include?("is invalid")
+  end
+
+  failure_message_for_should do |actual|
+    "expected that the #{attribute} attribute would be valid"
+  end
+
+  failure_message_for_should_not do |actual|
+    "expected that the #{attribute} attribute would be invalid"
+  end
+end