diff --git a/.travis.yml b/.travis.yml
index 88381ca..02227d0 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -5,8 +5,6 @@ install:
   - mkdir -p build/logs
 
 php:
-  - 7.0
-  - 7.1
   - 7.2
   - 7.3
   - 7.4
diff --git a/composer.json b/composer.json
index d588f37..9db2408 100644
--- a/composer.json
+++ b/composer.json
@@ -6,7 +6,7 @@
         "php": "^7.0.0"
     },
     "require-dev": {
-        "phpunit/phpunit": "^5.5.4",
+        "phpunit/phpunit": "^8.5.2",
         "satooshi/php-coveralls": "^1.0.1",
         "codacy/coverage": "^1.0.3"
     },
diff --git a/phpunit.xml.dist b/phpunit.xml.dist
index 8a7d274..3ece69a 100644
--- a/phpunit.xml.dist
+++ b/phpunit.xml.dist
@@ -4,7 +4,7 @@
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:noNamespaceSchemaLocation="http://schema.phpunit.de/5.5/phpunit.xsd"
         bootstrap="./vendor/autoload.php"
-        colors="auto"
+        colors="true"
 >
 
     <testsuites>
diff --git a/tests/Emails/EditableEmailTest.php b/tests/Emails/EditableEmailTest.php
index c8c2735..8471e08 100644
--- a/tests/Emails/EditableEmailTest.php
+++ b/tests/Emails/EditableEmailTest.php
@@ -5,8 +5,9 @@ namespace bkrukowski\TransparentEmail\Tests\Emails;
 use bkrukowski\TransparentEmail\Emails\EditableEmail;
 use bkrukowski\TransparentEmail\Emails\Email;
 use bkrukowski\TransparentEmail\Emails\EmailInterface;
+use PHPUnit\Framework\TestCase;
 
-class EditableEmailTest extends \PHPUnit_Framework_TestCase
+class EditableEmailTest extends TestCase
 {
     /**
      * @dataProvider providerRemoveFromLocalPart
@@ -19,7 +20,7 @@ class EditableEmailTest extends \PHPUnit_Framework_TestCase
         $editable = new EditableEmail($email);
         $new = $editable->removeFromLocalPart($toRemove);
         $this->assertNotSame($editable, $new);
-        $this->assertNotContains((string) $new, $toRemove);
+        $this->assertStringNotContainsString((string) $new, $toRemove);
         $this->assertSame($email->getDomain(), $new->getDomain());
     }
 
diff --git a/tests/Emails/EmailTest.php b/tests/Emails/EmailTest.php
index b03b08b..c559de7 100644
--- a/tests/Emails/EmailTest.php
+++ b/tests/Emails/EmailTest.php
@@ -6,8 +6,9 @@ namespace bkrukowski\TransparentEmail\Tests\Emails;
 
 use bkrukowski\TransparentEmail\Emails\Email;
 use bkrukowski\TransparentEmail\Emails\InvalidEmailException;
+use PHPUnit\Framework\TestCase;
 
-class EmailTest extends \PHPUnit_Framework_TestCase
+class EmailTest extends TestCase
 {
     /**
      * @dataProvider providerConstructor
diff --git a/tests/ServiceCollectorTest.php b/tests/ServiceCollectorTest.php
index 38f77f5..88eb430 100644
--- a/tests/ServiceCollectorTest.php
+++ b/tests/ServiceCollectorTest.php
@@ -6,8 +6,9 @@ namespace bkrukowski\TransparentEmail\Tests;
 
 use bkrukowski\TransparentEmail\ServiceCollector;
 use bkrukowski\TransparentEmail\Services\ServiceInterface;
+use PHPUnit\Framework\TestCase;
 
-class ServiceCollectorTest extends \PHPUnit_Framework_TestCase
+class ServiceCollectorTest extends TestCase
 {
     public function testAddService()
     {
diff --git a/tests/Services/AppsGoogleComTest.php b/tests/Services/AppsGoogleComTest.php
index 2ba0f4b..5598ad7 100644
--- a/tests/Services/AppsGoogleComTest.php
+++ b/tests/Services/AppsGoogleComTest.php
@@ -6,8 +6,9 @@ namespace bkrukowski\TransparentEmail\Tests\Services;
 
 use bkrukowski\TransparentEmail\Emails\Email;
 use bkrukowski\TransparentEmail\Services\AppsGoogleCom;
+use PHPUnit\Framework\TestCase;
 
-class AppsGoogleComTest extends \PHPUnit_Framework_TestCase
+class AppsGoogleComTest extends TestCase
 {
     /**
      * @dataProvider providerIsSupported
diff --git a/tests/Services/GmailComTest.php b/tests/Services/GmailComTest.php
index d5a7bad..196b1dc 100644
--- a/tests/Services/GmailComTest.php
+++ b/tests/Services/GmailComTest.php
@@ -6,8 +6,9 @@ namespace bkrukowski\TransparentEmail\Tests\Services;
 
 use bkrukowski\TransparentEmail\Emails\Email;
 use bkrukowski\TransparentEmail\Services\GmailCom;
+use PHPUnit\Framework\TestCase;
 
-class GmailComTest extends \PHPUnit_Framework_TestCase
+class GmailComTest extends TestCase
 {
     /**
      * @dataProvider providerGetPrimaryEmail
diff --git a/tests/Services/MailRUTest.php b/tests/Services/MailRUTest.php
index 7025088..fd7eee9 100644
--- a/tests/Services/MailRUTest.php
+++ b/tests/Services/MailRUTest.php
@@ -6,8 +6,9 @@ namespace bkrukowski\TransparentEmail\Tests\Services;
 
 use bkrukowski\TransparentEmail\Emails\Email;
 use bkrukowski\TransparentEmail\Services\MailRU;
+use PHPUnit\Framework\TestCase;
 
-class MailRUTest extends \PHPUnit_Framework_TestCase
+class MailRUTest extends TestCase
 {
     /**
      * @dataProvider providerGetPrimaryEmail
diff --git a/tests/Services/MultiDomainTest.php b/tests/Services/MultiDomainTest.php
index 3e6947f..2897b70 100644
--- a/tests/Services/MultiDomainTest.php
+++ b/tests/Services/MultiDomainTest.php
@@ -6,8 +6,9 @@ namespace bkrukowski\TransparentEmail\Tests\Services;
 
 use bkrukowski\TransparentEmail\Emails\Email;
 use bkrukowski\TransparentEmail\Services\MultiDomain;
+use PHPUnit\Framework\TestCase;
 
-class MultiDomainTest extends \PHPUnit_Framework_TestCase
+class MultiDomainTest extends TestCase
 {
     /**
      * @dataProvider providerIsSupported
diff --git a/tests/Services/OutlookComTest.php b/tests/Services/OutlookComTest.php
index c8451f5..d4f715c 100644
--- a/tests/Services/OutlookComTest.php
+++ b/tests/Services/OutlookComTest.php
@@ -6,8 +6,9 @@ namespace bkrukowski\TransparentEmail\Tests\Services;
 
 use bkrukowski\TransparentEmail\Emails\Email;
 use bkrukowski\TransparentEmail\Services\OutlookCom;
+use PHPUnit\Framework\TestCase;
 
-class OutlookComTest extends \PHPUnit_Framework_TestCase
+class OutlookComTest extends TestCase
 {
     /**
      * @dataProvider providerIsSupported
diff --git a/tests/Services/Www33MailComTest.php b/tests/Services/Www33MailComTest.php
index 891bc19..b449c35 100644
--- a/tests/Services/Www33MailComTest.php
+++ b/tests/Services/Www33MailComTest.php
@@ -6,8 +6,9 @@ namespace bkrukowski\TransparentEmail\Tests\Services;
 
 use bkrukowski\TransparentEmail\Emails\Email;
 use bkrukowski\TransparentEmail\Services\Www33MailCom;
+use PHPUnit\Framework\TestCase;
 
-class Www33MailComTest extends \PHPUnit_Framework_TestCase
+class Www33MailComTest extends TestCase
 {
     /**
      * @dataProvider providerIsSupported
diff --git a/tests/Services/YahooComTest.php b/tests/Services/YahooComTest.php
index 2763e5b..872beda 100644
--- a/tests/Services/YahooComTest.php
+++ b/tests/Services/YahooComTest.php
@@ -6,8 +6,9 @@ namespace bkrukowski\TransparentEmail\Tests\Services;
 
 use bkrukowski\TransparentEmail\Emails\Email;
 use bkrukowski\TransparentEmail\Services\YahooCom;
+use PHPUnit\Framework\TestCase;
 
-class YahooComTest extends \PHPUnit_Framework_TestCase
+class YahooComTest extends TestCase
 {
     /**
      * @dataProvider providerIsSupported
diff --git a/tests/Services/YandexRuTest.php b/tests/Services/YandexRuTest.php
index 74745f1..e41b495 100644
--- a/tests/Services/YandexRuTest.php
+++ b/tests/Services/YandexRuTest.php
@@ -6,8 +6,9 @@ namespace bkrukowski\TransparentEmail\Tests\Services;
 
 use bkrukowski\TransparentEmail\Emails\Email;
 use bkrukowski\TransparentEmail\Services\YandexRu;
+use PHPUnit\Framework\TestCase;
 
-class YandexRuTest extends \PHPUnit_Framework_TestCase
+class YandexRuTest extends TestCase
 {
     /**
      * @dataProvider providerGetPrimaryEmail
diff --git a/tests/TransparentEmailFactoryTest.php b/tests/TransparentEmailFactoryTest.php
index d84b919..26cfe6c 100644
--- a/tests/TransparentEmailFactoryTest.php
+++ b/tests/TransparentEmailFactoryTest.php
@@ -7,8 +7,9 @@ namespace bkrukowski\TransparentEmail\Tests;
 use bkrukowski\TransparentEmail\Emails\Email;
 use bkrukowski\TransparentEmail\Emails\EmailInterface;
 use bkrukowski\TransparentEmail\TransparentEmailFactory;
+use PHPUnit\Framework\TestCase;
 
-class TransparentEmailFactoryTest extends \PHPUnit_Framework_TestCase
+class TransparentEmailFactoryTest extends TestCase
 {
     /**
      * @dataProvider providerExpectedEmail
diff --git a/tests/TransparentEmailTest.php b/tests/TransparentEmailTest.php
index 6cc840f..e12b24b 100644
--- a/tests/TransparentEmailTest.php
+++ b/tests/TransparentEmailTest.php
@@ -11,8 +11,9 @@ use bkrukowski\TransparentEmail\ServiceCollectorInterface;
 use bkrukowski\TransparentEmail\Services\TlenPl;
 use bkrukowski\TransparentEmail\TransparentEmail;
 use bkrukowski\TransparentEmail\TransparentEmailFactory;
+use PHPUnit\Framework\TestCase;
 
-class TransparentEmailTest extends \PHPUnit_Framework_TestCase
+class TransparentEmailTest extends TestCase
 {
     /**
      * @dataProvider providerGetPrimaryEmail