diff --git a/.travis.yml b/.travis.yml
index 7224ddc..7abac1a 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -4,6 +4,8 @@ php:
   - 7.0
   - 7.1
   - 7.2
+  - 7.3
+  - 7.4
 
 before_script:
   - composer install
diff --git a/tests/Rules/AcceptedTest.php b/tests/Rules/AcceptedTest.php
index dbad471..b5fb746 100644
--- a/tests/Rules/AcceptedTest.php
+++ b/tests/Rules/AcceptedTest.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace Rakit\Validation\Tests;
+namespace Rakit\Validation\Tests\Rules;
 
 use Rakit\Validation\Rules\Accepted;
 use PHPUnit\Framework\TestCase;
diff --git a/tests/Rules/AfterTest.php b/tests/Rules/AfterTest.php
index fffacc7..0b5c8bf 100644
--- a/tests/Rules/AfterTest.php
+++ b/tests/Rules/AfterTest.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace Rakit\Validation\Tests;
+namespace Rakit\Validation\Tests\Rules;
 
 use Rakit\Validation\Rules\After;
 use PHPUnit\Framework\TestCase;
diff --git a/tests/Rules/AlphaDashTest.php b/tests/Rules/AlphaDashTest.php
index 269d383..f2b148a 100644
--- a/tests/Rules/AlphaDashTest.php
+++ b/tests/Rules/AlphaDashTest.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace Rakit\Validation\Tests;
+namespace Rakit\Validation\Tests\Rules;
 
 use Rakit\Validation\Rules\AlphaDash;
 use PHPUnit\Framework\TestCase;
diff --git a/tests/Rules/AlphaNumTest.php b/tests/Rules/AlphaNumTest.php
index dbbff98..d6ca50f 100644
--- a/tests/Rules/AlphaNumTest.php
+++ b/tests/Rules/AlphaNumTest.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace Rakit\Validation\Tests;
+namespace Rakit\Validation\Tests\Rules;
 
 use Rakit\Validation\Rules\AlphaNum;
 use PHPUnit\Framework\TestCase;
diff --git a/tests/Rules/AlphaSpacesTest.php b/tests/Rules/AlphaSpacesTest.php
index 2bd1d56..37effed 100644
--- a/tests/Rules/AlphaSpacesTest.php
+++ b/tests/Rules/AlphaSpacesTest.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace Rakit\Validation\Tests;
+namespace Rakit\Validation\Tests\Rules;
 
 use Rakit\Validation\Rules\AlphaSpaces;
 use PHPUnit\Framework\TestCase;
diff --git a/tests/Rules/AlphaTest.php b/tests/Rules/AlphaTest.php
index 11e6b4b..02be524 100644
--- a/tests/Rules/AlphaTest.php
+++ b/tests/Rules/AlphaTest.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace Rakit\Validation\Tests;
+namespace Rakit\Validation\Tests\Rules;
 
 use Rakit\Validation\Rules\Alpha;
 use PHPUnit\Framework\TestCase;
diff --git a/tests/Rules/BeforeTest.php b/tests/Rules/BeforeTest.php
index 5b89cb8..8af7eb1 100644
--- a/tests/Rules/BeforeTest.php
+++ b/tests/Rules/BeforeTest.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace Rakit\Validation\Tests;
+namespace Rakit\Validation\Tests\Rules;
 
 use Rakit\Validation\Rules\Before;
 use PHPUnit\Framework\TestCase;
diff --git a/tests/Rules/BetweenTest.php b/tests/Rules/BetweenTest.php
index 7bcf5f0..ea01596 100644
--- a/tests/Rules/BetweenTest.php
+++ b/tests/Rules/BetweenTest.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace Rakit\Validation\Tests;
+namespace Rakit\Validation\Tests\Rules;
 
 use Rakit\Validation\Rules\Between;
 use PHPUnit\Framework\TestCase;
diff --git a/tests/Rules/BooleanTest.php b/tests/Rules/BooleanTest.php
index 8c4b2e2..1eaeac3 100644
--- a/tests/Rules/BooleanTest.php
+++ b/tests/Rules/BooleanTest.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace Rakit\Validation\Tests;
+namespace Rakit\Validation\Tests\Rules;
 
 use PHPUnit\Framework\TestCase;
 use Rakit\Validation\Rules\Boolean;
diff --git a/tests/Rules/CallbackTest.php b/tests/Rules/CallbackTest.php
index de36ce8..8a16599 100644
--- a/tests/Rules/CallbackTest.php
+++ b/tests/Rules/CallbackTest.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace Rakit\Validation\Tests;
+namespace Rakit\Validation\Tests\Rules;
 
 use Rakit\Validation\Rules\Callback;
 use PHPUnit\Framework\TestCase;
diff --git a/tests/Rules/DateTest.php b/tests/Rules/DateTest.php
index 1619e28..71b21ae 100644
--- a/tests/Rules/DateTest.php
+++ b/tests/Rules/DateTest.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace Rakit\Validation\Tests;
+namespace Rakit\Validation\Tests\Rules;
 
 use Rakit\Validation\Rules\Date;
 use PHPUnit\Framework\TestCase;
diff --git a/tests/Rules/DefaultsTest.php b/tests/Rules/DefaultsTest.php
index e3b637c..deaab56 100644
--- a/tests/Rules/DefaultsTest.php
+++ b/tests/Rules/DefaultsTest.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace Rakit\Validation\Tests;
+namespace Rakit\Validation\Tests\Rules;
 
 use Rakit\Validation\Rules\Defaults;
 use PHPUnit\Framework\TestCase;
diff --git a/tests/Rules/DigitsBetweenTest.php b/tests/Rules/DigitsBetweenTest.php
index 0602663..c792727 100644
--- a/tests/Rules/DigitsBetweenTest.php
+++ b/tests/Rules/DigitsBetweenTest.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace Rakit\Validation\Tests;
+namespace Rakit\Validation\Tests\Rules;
 
 use Rakit\Validation\Rules\DigitsBetween;
 use PHPUnit\Framework\TestCase;
diff --git a/tests/Rules/DigitsTest.php b/tests/Rules/DigitsTest.php
index 7d9db2e..8214816 100644
--- a/tests/Rules/DigitsTest.php
+++ b/tests/Rules/DigitsTest.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace Rakit\Validation\Tests;
+namespace Rakit\Validation\Tests\Rules;
 
 use Rakit\Validation\Rules\Digits;
 use PHPUnit\Framework\TestCase;
diff --git a/tests/Rules/EmailTest.php b/tests/Rules/EmailTest.php
index 66ba2fc..1c31ceb 100644
--- a/tests/Rules/EmailTest.php
+++ b/tests/Rules/EmailTest.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace Rakit\Validation\Tests;
+namespace Rakit\Validation\Tests\Rules;
 
 use Rakit\Validation\Rules\Email;
 use PHPUnit\Framework\TestCase;
diff --git a/tests/Rules/ExtensionTest.php b/tests/Rules/ExtensionTest.php
index 88897eb..e1fd51e 100644
--- a/tests/Rules/ExtensionTest.php
+++ b/tests/Rules/ExtensionTest.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace Rakit\Validation\Tests;
+namespace Rakit\Validation\Tests\Rules;
 
 use Rakit\Validation\Rules\Extension;
 use PHPUnit\Framework\TestCase;
diff --git a/tests/Rules/InTest.php b/tests/Rules/InTest.php
index 29e86be..dcb5a5c 100644
--- a/tests/Rules/InTest.php
+++ b/tests/Rules/InTest.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace Rakit\Validation\Tests;
+namespace Rakit\Validation\Tests\Rules;
 
 use Rakit\Validation\Rules\In;
 use PHPUnit\Framework\TestCase;
diff --git a/tests/Rules/IntegerTest.php b/tests/Rules/IntegerTest.php
index 101a4d4..8fd92ca 100644
--- a/tests/Rules/IntegerTest.php
+++ b/tests/Rules/IntegerTest.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace Rakit\Validation\Tests;
+namespace Rakit\Validation\Tests\Rules;
 
 use Rakit\Validation\Rules\Integer;
 use PHPUnit\Framework\TestCase;
diff --git a/tests/Rules/IpTest.php b/tests/Rules/IpTest.php
index 0eac7eb..3e5ee2e 100644
--- a/tests/Rules/IpTest.php
+++ b/tests/Rules/IpTest.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace Rakit\Validation\Tests;
+namespace Rakit\Validation\Tests\Rules;
 
 use Rakit\Validation\Rules\Ip;
 use PHPUnit\Framework\TestCase;
diff --git a/tests/Rules/Ipv4Test.php b/tests/Rules/Ipv4Test.php
index 41bd6fe..9f3d11e 100644
--- a/tests/Rules/Ipv4Test.php
+++ b/tests/Rules/Ipv4Test.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace Rakit\Validation\Tests;
+namespace Rakit\Validation\Tests\Rules;
 
 use Rakit\Validation\Rules\Ipv4;
 use PHPUnit\Framework\TestCase;
diff --git a/tests/Rules/Ipv6Test.php b/tests/Rules/Ipv6Test.php
index f3ab8d3..b0ba1e3 100644
--- a/tests/Rules/Ipv6Test.php
+++ b/tests/Rules/Ipv6Test.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace Rakit\Validation\Tests;
+namespace Rakit\Validation\Tests\Rules;
 
 use Rakit\Validation\Rules\Ipv6;
 use PHPUnit\Framework\TestCase;
diff --git a/tests/Rules/JsonTest.php b/tests/Rules/JsonTest.php
index 9daa860..388e826 100644
--- a/tests/Rules/JsonTest.php
+++ b/tests/Rules/JsonTest.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace Rakit\Validation\Tests;
+namespace Rakit\Validation\Tests\Rules;
 
 use Rakit\Validation\Rules\Json;
 use PHPUnit\Framework\TestCase;
diff --git a/tests/Rules/LowercaseTest.php b/tests/Rules/LowercaseTest.php
index dcc17b4..83c4b22 100644
--- a/tests/Rules/LowercaseTest.php
+++ b/tests/Rules/LowercaseTest.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace Rakit\Validation\Tests;
+namespace Rakit\Validation\Tests\Rules;
 
 use Rakit\Validation\Rules\Lowercase;
 use PHPUnit\Framework\TestCase;
diff --git a/tests/Rules/MaxTest.php b/tests/Rules/MaxTest.php
index 8c9087b..2ffb379 100644
--- a/tests/Rules/MaxTest.php
+++ b/tests/Rules/MaxTest.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace Rakit\Validation\Tests;
+namespace Rakit\Validation\Tests\Rules;
 
 use Rakit\Validation\Rules\Max;
 use PHPUnit\Framework\TestCase;
diff --git a/tests/Rules/MimesTest.php b/tests/Rules/MimesTest.php
index 5056f96..fc3c994 100644
--- a/tests/Rules/MimesTest.php
+++ b/tests/Rules/MimesTest.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace Rakit\Validation\Tests;
+namespace Rakit\Validation\Tests\Rules;
 
 use Rakit\Validation\Rules\Mimes;
 use PHPUnit\Framework\TestCase;
diff --git a/tests/Rules/MinTest.php b/tests/Rules/MinTest.php
index 98b8b99..1d6eec6 100644
--- a/tests/Rules/MinTest.php
+++ b/tests/Rules/MinTest.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace Rakit\Validation\Tests;
+namespace Rakit\Validation\Tests\Rules;
 
 use Rakit\Validation\Rules\Min;
 use PHPUnit\Framework\TestCase;
diff --git a/tests/Rules/NotInTest.php b/tests/Rules/NotInTest.php
index 34f0523..d77b605 100644
--- a/tests/Rules/NotInTest.php
+++ b/tests/Rules/NotInTest.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace Rakit\Validation\Tests;
+namespace Rakit\Validation\Tests\Rules;
 
 use Rakit\Validation\Rules\NotIn;
 use PHPUnit\Framework\TestCase;
diff --git a/tests/Rules/NumericTest.php b/tests/Rules/NumericTest.php
index cc309df..a39f576 100644
--- a/tests/Rules/NumericTest.php
+++ b/tests/Rules/NumericTest.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace Rakit\Validation\Tests;
+namespace Rakit\Validation\Tests\Rules;
 
 use Rakit\Validation\Rules\Numeric;
 use PHPUnit\Framework\TestCase;
diff --git a/tests/Rules/RegexTest.php b/tests/Rules/RegexTest.php
index d5d5f35..7cef919 100644
--- a/tests/Rules/RegexTest.php
+++ b/tests/Rules/RegexTest.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace Rakit\Validation\Tests;
+namespace Rakit\Validation\Tests\Rules;
 
 use Rakit\Validation\Rules\Regex;
 use PHPUnit\Framework\TestCase;
diff --git a/tests/Rules/RequiredTest.php b/tests/Rules/RequiredTest.php
index 3f3535f..d1128c9 100644
--- a/tests/Rules/RequiredTest.php
+++ b/tests/Rules/RequiredTest.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace Rakit\Validation\Tests;
+namespace Rakit\Validation\Tests\Rules;
 
 use Rakit\Validation\Rules\Required;
 use PHPUnit\Framework\TestCase;
diff --git a/tests/Rules/TypeArrayTest.php b/tests/Rules/TypeArrayTest.php
index 56e8e60..da9ef71 100644
--- a/tests/Rules/TypeArrayTest.php
+++ b/tests/Rules/TypeArrayTest.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace Rakit\Validation\Tests;
+namespace Rakit\Validation\Tests\Rules;
 
 use Rakit\Validation\Rules\TypeArray;
 use PHPUnit\Framework\TestCase;
diff --git a/tests/Rules/UploadedFileTest.php b/tests/Rules/UploadedFileTest.php
index 3f0f6f5..207d39b 100644
--- a/tests/Rules/UploadedFileTest.php
+++ b/tests/Rules/UploadedFileTest.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace Rakit\Validation\Tests;
+namespace Rakit\Validation\Tests\Rules;
 
 use Rakit\Validation\Rules\UploadedFile;
 use PHPUnit\Framework\TestCase;
diff --git a/tests/Rules/UppercaseTest.php b/tests/Rules/UppercaseTest.php
index cf7bdc8..0e9c5be 100644
--- a/tests/Rules/UppercaseTest.php
+++ b/tests/Rules/UppercaseTest.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace Rakit\Validation\Tests;
+namespace Rakit\Validation\Tests\Rules;
 
 use Rakit\Validation\Rules\Uppercase;
 use PHPUnit\Framework\TestCase;
diff --git a/tests/Rules/UrlTest.php b/tests/Rules/UrlTest.php
index d91fe3d..ed91928 100644
--- a/tests/Rules/UrlTest.php
+++ b/tests/Rules/UrlTest.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace Rakit\Validation\Tests;
+namespace Rakit\Validation\Tests\Rules;
 
 use Rakit\Validation\Rules\Url;
 use PHPUnit\Framework\TestCase;
diff --git a/tests/ValidatorTest.php b/tests/ValidatorTest.php
index a17a123..dd5b149 100644
--- a/tests/ValidatorTest.php
+++ b/tests/ValidatorTest.php
@@ -1313,7 +1313,7 @@ public function testGetValidData()
         ], $validData);
 
         $stuffs = $validData['stuffs'];
-        $this->assertFalse(isset($stuffs['three']));
+        $this->assertArrayNotHasKey('three', $stuffs);
     }
 
     public function testGetInvalidData()
@@ -1366,8 +1366,8 @@ public function testGetInvalidData()
         ], $invalidData);
 
         $stuffs = $invalidData['stuffs'];
-        $this->assertFalse(isset($stuffs['one']));
-        $this->assertFalse(isset($stuffs['two']));
+        $this->assertArrayNotHasKey('one', $stuffs);
+        $this->assertArrayNotHasKey('two', $stuffs);
     }
 
     public function testRuleInInvalidMessages()