diff --git a/tests/Emails/EditableEmailTest.php b/tests/Emails/EditableEmailTest.php
index 78e2cf0..cd2f60b 100644
--- a/tests/Emails/EditableEmailTest.php
+++ b/tests/Emails/EditableEmailTest.php
@@ -23,7 +23,7 @@ class EditableEmailTest extends \PHPUnit_Framework_TestCase
         $this->assertSame($email->getDomain(), $new->getDomain());
     }
 
-    public function providerRemoveFromLocalPart()
+    public function providerRemoveFromLocalPart() : array
     {
         return [
             [new Email('jane.doe.1990@gmail.com'), '.'],
@@ -47,7 +47,7 @@ class EditableEmailTest extends \PHPUnit_Framework_TestCase
         $this->assertSame($email->getDomain(), $editable->getDomain());
     }
 
-    public function providerRemoveSuffixAlias()
+    public function providerRemoveSuffixAlias() : array
     {
         return [
             [new Email('John.Doe+alias@gmail.com', true), '+', 'John.Doe@gmail.com'],
@@ -71,7 +71,7 @@ class EditableEmailTest extends \PHPUnit_Framework_TestCase
         $this->assertSame($email->getLocalPart(), $new->getLocalPart());
     }
 
-    public function providerSetDomain()
+    public function providerSetDomain() : array
     {
         return [
             [new Email('jane.doe@foo.bar'), 'gmail.com'],
@@ -95,7 +95,7 @@ class EditableEmailTest extends \PHPUnit_Framework_TestCase
         $this->assertSame($email->getDomain(), $new->getDomain());
     }
 
-    public function providerSetLocalPart()
+    public function providerSetLocalPart() : array
     {
         return [
             [new Email('jane.doe@foo.bar'), 'jane'],
@@ -120,7 +120,7 @@ class EditableEmailTest extends \PHPUnit_Framework_TestCase
         $this->assertSame($email->getDomain(), $new->getDomain());
     }
 
-    public function providerLowerCaseLocalPartIf()
+    public function providerLowerCaseLocalPartIf() : array
     {
         return [
             [new Email('john.doe@example.com', true), false, true],
diff --git a/tests/Emails/EmailTest.php b/tests/Emails/EmailTest.php
index c5b1fc0..b03b08b 100644
--- a/tests/Emails/EmailTest.php
+++ b/tests/Emails/EmailTest.php
@@ -33,7 +33,7 @@ class EmailTest extends \PHPUnit_Framework_TestCase
         $this->assertSame($domain, $object->getDomain());
     }
 
-    public function providerConstructor()
+    public function providerConstructor() : array
     {
         return [
             ['john doe@example.com', true],
diff --git a/tests/Services/AppsGoogleComTest.php b/tests/Services/AppsGoogleComTest.php
index bcb0ba0..2ba0f4b 100644
--- a/tests/Services/AppsGoogleComTest.php
+++ b/tests/Services/AppsGoogleComTest.php
@@ -20,7 +20,7 @@ class AppsGoogleComTest extends \PHPUnit_Framework_TestCase
         $this->assertSame($result, (new AppsGoogleCom())->isSupported(new Email('Jane.Doe@' . $domain, true)));
     }
 
-    public function providerIsSupported()
+    public function providerIsSupported() : array
     {
         return [
             ['example.com', false],
diff --git a/tests/Services/GmailComTest.php b/tests/Services/GmailComTest.php
index 3eac764..d5a7bad 100644
--- a/tests/Services/GmailComTest.php
+++ b/tests/Services/GmailComTest.php
@@ -20,7 +20,7 @@ class GmailComTest extends \PHPUnit_Framework_TestCase
         $this->assertEquals($outputEmail, (new GmailCom())->getPrimaryEmail(new Email($inputEmail)));
     }
 
-    public function providerGetPrimaryEmail()
+    public function providerGetPrimaryEmail() : array
     {
         return [
             ['foo.bar@gmail.com', 'foobar@gmail.com'],
@@ -42,7 +42,7 @@ class GmailComTest extends \PHPUnit_Framework_TestCase
         $this->assertSame($result, (new GmailCom())->isSupported(new Email('Jane.Doe@' . $domain)));
     }
 
-    public function providerIsSupported()
+    public function providerIsSupported() : array
     {
         return [
             ['gmail.com', true],
diff --git a/tests/Services/MultiDomainTest.php b/tests/Services/MultiDomainTest.php
index 60f843e..3e6947f 100644
--- a/tests/Services/MultiDomainTest.php
+++ b/tests/Services/MultiDomainTest.php
@@ -21,7 +21,7 @@ class MultiDomainTest extends \PHPUnit_Framework_TestCase
         $this->assertSame($expected, $mock->isSupported(new Email('Jane.Doe@' . $domain, true)));
     }
 
-    public function providerIsSupported()
+    public function providerIsSupported() : array
     {
         return [
             [$this->getMultiDomainMock('foo.bar', ['foo.bar']), 'gmail.com', false],
@@ -42,7 +42,7 @@ class MultiDomainTest extends \PHPUnit_Framework_TestCase
         $this->assertEquals($expectedEmail, $mock->getPrimaryEmail(new Email($email, true)));
     }
 
-    public function providerGetPrimaryDomain()
+    public function providerGetPrimaryDomain() : array
     {
         return [
             [$this->getMultiDomainMock('foo.bar', ['foo.bar', 'foo.bar2']), 'name@foo.bar', 'name@foo.bar'],
diff --git a/tests/Services/OutlookComTest.php b/tests/Services/OutlookComTest.php
index 4849971..c8451f5 100644
--- a/tests/Services/OutlookComTest.php
+++ b/tests/Services/OutlookComTest.php
@@ -20,7 +20,7 @@ class OutlookComTest extends \PHPUnit_Framework_TestCase
         $this->assertSame($result, (new OutlookCom())->isSupported(new Email('Jane.Doe@' . $domain, true)));
     }
 
-    public function providerIsSupported()
+    public function providerIsSupported() : array
     {
         return [
             ['outlook.com', true],
@@ -43,7 +43,7 @@ class OutlookComTest extends \PHPUnit_Framework_TestCase
         $this->assertEquals($expectedEmail, (new OutlookCom())->getPrimaryEmail(new Email($inputEmail, true)));
     }
 
-    public function providerGetPrimaryEmail()
+    public function providerGetPrimaryEmail() : array
     {
         return [
             ['janedoe@outlook.com', 'janedoe@outlook.com'],
diff --git a/tests/Services/Www33MailComTest.php b/tests/Services/Www33MailComTest.php
index e6a5ef4..891bc19 100644
--- a/tests/Services/Www33MailComTest.php
+++ b/tests/Services/Www33MailComTest.php
@@ -20,7 +20,7 @@ class Www33MailComTest extends \PHPUnit_Framework_TestCase
         $this->assertSame($isSupported, (new Www33MailCom())->isSupported(new Email('Jane.Doe@' . $domain, true)));
     }
 
-    public function providerIsSupported()
+    public function providerIsSupported() : array
     {
         return [
             ['foo.33mail.com', true],
@@ -42,7 +42,7 @@ class Www33MailComTest extends \PHPUnit_Framework_TestCase
         $this->assertEquals($expectedEmail, (new Www33MailCom())->getPrimaryEmail(new Email($inputEmail, true)));
     }
 
-    public function providerGetPrimaryEmail()
+    public function providerGetPrimaryEmail() : array
     {
         return [
             ['qwerty@name.33mail.com', 'name@name.33mail.com'],
diff --git a/tests/Services/YahooComTest.php b/tests/Services/YahooComTest.php
index 7ce476c..2763e5b 100644
--- a/tests/Services/YahooComTest.php
+++ b/tests/Services/YahooComTest.php
@@ -20,7 +20,7 @@ class YahooComTest extends \PHPUnit_Framework_TestCase
         $this->assertSame($result, (new YahooCom())->isSupported(new Email('Jane.Doe@' . $domain, true)));
     }
 
-    public function providerIsSupported()
+    public function providerIsSupported() : array
     {
         return [
             ['yahoo.com', true],
@@ -44,7 +44,7 @@ class YahooComTest extends \PHPUnit_Framework_TestCase
         $this->assertEquals($expectedEmail, (new YahooCom())->getPrimaryEmail(new Email($inputEmail, true)));
     }
 
-    public function providerGetPrimaryEmail()
+    public function providerGetPrimaryEmail() : array
     {
         return [
             ['janedoe@yahoo.com', 'janedoe@yahoo.com'],
diff --git a/tests/TransparentEmailTest.php b/tests/TransparentEmailTest.php
index 7a78650..bd1c56f 100644
--- a/tests/TransparentEmailTest.php
+++ b/tests/TransparentEmailTest.php
@@ -31,7 +31,7 @@ class TransparentEmailTest extends \PHPUnit_Framework_TestCase
         $this->assertEquals($expectedEmail, $transparentEmail->getPrimaryEmail(new Email($email, $caseSensitive)));
     }
 
-    public function providerGetPrimaryEmail()
+    public function providerGetPrimaryEmail() : array
     {
         $emptyServiceCollector = $this->createServiceCollector();
         $tlenServiceCollector = $this->createServiceCollector([TlenPl::class]);
@@ -62,7 +62,7 @@ class TransparentEmailTest extends \PHPUnit_Framework_TestCase
         $this->assertEquals($expectedEmail, (TransparentEmailFactory::createDefault())->getPrimaryEmail($inputEmail));
     }
 
-    public function providerDefault()
+    public function providerDefault() : array
     {
         return [
             [new Email('John.Doe+spam@gmail.com', true), 'johndoe@gmail.com'],