diff --git a/.php_cs.dist b/.php_cs.dist
index d5294a39..d62705e6 100644
--- a/.php_cs.dist
+++ b/.php_cs.dist
@@ -1,13 +1,12 @@
 <?php
 
 return PhpCsFixer\Config::create()
-    ->setRules(array(
+    ->setRules([
         '@Symfony' => true,
         '@Symfony:risky' => true,
-        '@PHPUnit48Migration:risky' => true,
-        'php_unit_no_expectation_annotation' => false, // part of `PHPUnitXYMigration:risky` ruleset, to be enabled when PHPUnit 4.x support will be dropped, as we don't want to rewrite exceptions handling twice
+        '@PHPUnit75Migration:risky' => true,
         'array_syntax' => array('syntax' => 'short'),
         'protected_to_private' => false,
-    ))
+    ])
     ->setRiskyAllowed(true)
 ;
diff --git a/Command/DebugCommand.php b/Command/DebugCommand.php
index 320de536..5d602d7e 100644
--- a/Command/DebugCommand.php
+++ b/Command/DebugCommand.php
@@ -50,6 +50,9 @@ protected function configure()
         ;
     }
 
+    /**
+     * @return int
+     */
     protected function execute(InputInterface $input, OutputInterface $output)
     {
         $this->io = new SymfonyStyle($input, $output);
@@ -60,6 +63,8 @@ protected function execute(InputInterface $input, OutputInterface $output)
         } else {
             $this->outputMailers();
         }
+
+        return 0;
     }
 
     protected function outputMailers($routes = null)
diff --git a/Command/NewEmailCommand.php b/Command/NewEmailCommand.php
index b53a2a0b..99981c09 100644
--- a/Command/NewEmailCommand.php
+++ b/Command/NewEmailCommand.php
@@ -67,7 +67,7 @@ protected function initialize(InputInterface $input, OutputInterface $output)
     }
 
     /**
-     * {@inheritdoc}
+     * @return int
      */
     protected function execute(InputInterface $input, OutputInterface $output)
     {
@@ -96,6 +96,8 @@ protected function execute(InputInterface $input, OutputInterface $output)
         $sentMessages = $mailer->send($message);
 
         $this->io->success(sprintf('%s emails were successfully sent.', $sentMessages));
+
+        return 0;
     }
 
     /**
diff --git a/Command/SendEmailCommand.php b/Command/SendEmailCommand.php
index e8c3e638..5646d95a 100644
--- a/Command/SendEmailCommand.php
+++ b/Command/SendEmailCommand.php
@@ -51,6 +51,9 @@ protected function configure()
         ;
     }
 
+    /**
+     * @return int
+     */
     protected function execute(InputInterface $input, OutputInterface $output)
     {
         $this->io = new SymfonyStyle($input, $output);
@@ -64,6 +67,8 @@ protected function execute(InputInterface $input, OutputInterface $output)
                 $this->processMailer($name, $input, $output);
             }
         }
+
+        return 0;
     }
 
     private function processMailer($name, InputInterface $input, OutputInterface $output)
diff --git a/Tests/Command/SendEmailCommandTest.php b/Tests/Command/SendEmailCommandTest.php
index 14ce2a0d..a22849ce 100644
--- a/Tests/Command/SendEmailCommandTest.php
+++ b/Tests/Command/SendEmailCommandTest.php
@@ -20,7 +20,7 @@ public function testRecoverSpoolTransport()
             ->expects($this->once())
             ->method('flushQueue')
             ->with($realTransport)
-            ->will($this->returnValue(5))
+            ->willReturn(5)
         ;
 
         $spoolTransport = new \Swift_Transport_SpoolTransport(new \Swift_Events_SimpleEventDispatcher(), $spool);
@@ -96,7 +96,7 @@ public function testRecoverLoadbalancedTransportWithSpool()
             ->expects($this->once())
             ->method('flushQueue')
             ->with($realTransport)
-            ->will($this->returnValue(7))
+            ->willReturn(7)
         ;
 
         $spoolTransport = new \Swift_Transport_SpoolTransport(new \Swift_Events_SimpleEventDispatcher(), $spool);
diff --git a/Tests/DependencyInjection/SwiftmailerExtensionTest.php b/Tests/DependencyInjection/SwiftmailerExtensionTest.php
index 36fb721e..f9cdb657 100644
--- a/Tests/DependencyInjection/SwiftmailerExtensionTest.php
+++ b/Tests/DependencyInjection/SwiftmailerExtensionTest.php
@@ -52,7 +52,7 @@ public function getConfigTypes()
     public function testDefaultConfig($type)
     {
         $requestContext = $this->getMockBuilder('Symfony\Component\Routing\RequestContext')->setMethods(['getHost'])->getMock();
-        $requestContext->expects($this->once())->method('getHost')->will($this->returnValue('example.org'));
+        $requestContext->expects($this->once())->method('getHost')->willReturn('example.org');
         $services = ['router.request_context' => $requestContext];
 
         $container = $this->loadContainerFromFile('empty', $type, $services);
@@ -83,7 +83,7 @@ public function testSendmailConfig($type)
     {
         // Local domain is specified explicitly, so the request context host is ignored.
         $requestContext = $this->getMockBuilder('Symfony\Component\Routing\RequestContext')->setMethods(['getHost'])->getMock();
-        $requestContext->expects($this->any())->method('getHost')->will($this->returnValue('example.org'));
+        $requestContext->expects($this->any())->method('getHost')->willReturn('example.org');
         $services = ['router.request_context' => $requestContext];
 
         $container = $this->loadContainerFromFile('sendmail', $type, $services);
@@ -286,10 +286,11 @@ public function testServiceSpool($type)
 
     /**
      * @dataProvider getConfigTypes
-     * @expectedException \Symfony\Component\Config\Definition\Exception\InvalidConfigurationException
      */
     public function testInvalidServiceSpool($type)
     {
+        $this->expectException(\Symfony\Component\Config\Definition\Exception\InvalidConfigurationException::class);
+
         $this->loadContainerFromFile('spool_service_invalid', $type);
     }
 
diff --git a/Tests/DependencyInjection/SwiftmailerTransportFactoryTest.php b/Tests/DependencyInjection/SwiftmailerTransportFactoryTest.php
index 95de98d4..56f7864b 100644
--- a/Tests/DependencyInjection/SwiftmailerTransportFactoryTest.php
+++ b/Tests/DependencyInjection/SwiftmailerTransportFactoryTest.php
@@ -79,12 +79,11 @@ public function testCreateTransportWithNull()
         $this->assertInstanceOf('Swift_Transport_NullTransport', $transport);
     }
 
-    /**
-     * @expectedException \InvalidArgumentException
-     * @expectedExceptionMessage The fake_encryption encryption is not supported
-     */
     public function testCreateTransportWithWrongEncryption()
     {
+        $this->expectException(\InvalidArgumentException::class);
+        $this->expectExceptionMessage('The fake_encryption encryption is not supported');
+
         SwiftmailerTransportFactory::createTransport(
             [
                 'transport' => 'smtp',
@@ -103,12 +102,11 @@ public function testCreateTransportWithWrongEncryption()
         );
     }
 
-    /**
-     * @expectedException \InvalidArgumentException
-     * @expectedExceptionMessage The fake_auth authentication mode is not supported
-     */
     public function testCreateTransportWithWrongAuthMode()
     {
+        $this->expectException(\InvalidArgumentException::class);
+        $this->expectExceptionMessage('The fake_auth authentication mode is not supported');
+
         SwiftmailerTransportFactory::createTransport(
             [
                 'transport' => 'smtp',
@@ -161,12 +159,11 @@ public function testCreateTransportWithSmtpAndWithoutRequestContext()
         $this->assertSame($authHandler->getAuthMode(), $options['auth_mode']);
     }
 
-    /**
-     * @expectedException \InvalidArgumentException
-     * @expectedExceptionMessage The Swiftmailer URL "smtp://localhost:25&auth_mode=cra-md5" is not valid.
-     */
     public function testCreateTransportWithBadURLFormat()
     {
+        $this->expectException(\InvalidArgumentException::class);
+        $this->expectExceptionMessage('The Swiftmailer URL "smtp://localhost:25&auth_mode=cra-md5" is not valid.');
+
         $options = [
             'url' => 'smtp://localhost:25&auth_mode=cra-md5',
             'transport' => 'smtp',
diff --git a/composer.json b/composer.json
index 609b16c7..bbe796e5 100644
--- a/composer.json
+++ b/composer.json
@@ -18,15 +18,15 @@
     "require": {
         "php": ">=7.0.0",
         "swiftmailer/swiftmailer": "^6.1.3",
-        "symfony/dependency-injection": "~2.7|~3.3|~4.0",
-        "symfony/http-kernel": "~2.7|~3.3|~4.0",
-        "symfony/config": "~2.8|~3.3|~4.0"
+        "symfony/dependency-injection": "^3.4|^4.0|^5.0",
+        "symfony/http-kernel": "^3.4|^4.0|^5.0",
+        "symfony/config": "^3.4|^4.0|^5.0"
     },
     "require-dev": {
-        "symfony/console": "~2.7|~3.3|~4.0",
-        "symfony/framework-bundle": "~2.7|~3.3|~4.0",
-        "symfony/phpunit-bridge": "^3.4.32|^4.3.5",
-        "symfony/yaml": "~2.7|~3.3|~4.0"
+        "symfony/console": "^3.4|^4.0|^5.0",
+        "symfony/framework-bundle": "^3.4|^4.0|^5.0",
+        "symfony/phpunit-bridge": "^3.4.32|^4.3.5|^5.0",
+        "symfony/yaml": "^3.4|^4.0|^5.0"
     },
     "conflict": {
         "twig/twig": "<1.41|<2.10"