diff --git a/.travis.yml b/.travis.yml
index 1b5ca1c..ab97a91 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,8 +1,8 @@
 language: php
 
 php:
-  - 7.1
   - 7.2
+  - 7.3
 
 env:
   matrix:
@@ -15,5 +15,5 @@ before_script:
 script:
   - composer run build
 
-after_script:
-  - composer run coveralls
+after_success:
+  - travis_retry php vendor/bin/php-coveralls -v
diff --git a/README.md b/README.md
index 1f22193..72ae0bb 100644
--- a/README.md
+++ b/README.md
@@ -50,7 +50,7 @@ class User
 
 Requirements
 ------------
-Works with PHP 7.1 or higher.
+Works with PHP 7.2 or higher.
 
 Submitting bugs and feature requests
 ------------------------------------
@@ -65,6 +65,9 @@ Thanks [Vašek Purchart](http://www.vasekpurchart.cz/) for ideas how to test Sym
 Changelog
 ----------
 
+## 4.0.0 (2018-XX-XX)
+- [#6](../../pull/6) dropped support for PHP 7.1 as it is no longer supported
+
 ## 3.0.0 (2018-01-07)
 - [#3](https://github.com/mhujer/jms-serializer-uuid-bundle/pull/3) Added Symfony 4.0 support, dropped support for Symfony 2. Requires PHP 7.1.
 
diff --git a/composer.json b/composer.json
index be88a28..d6453e2 100644
--- a/composer.json
+++ b/composer.json
@@ -18,7 +18,7 @@
 		}
 	],
 	"require": {
-		"php": "^7.1",
+		"php": "~7.2",
 		"jms/serializer-bundle": "~1.0 || ~2.0",
 		"mhujer/jms-serializer-uuid": "~2.0",
 		"symfony/config": "~3.0 || ~4.0",
@@ -27,11 +27,12 @@
 		"symfony/yaml": "~3.0 || ~4.0"
 	},
 	"require-dev": {
-		"consistence/coding-standard": "2.3",
-		"jakub-onderka/php-parallel-lint": "0.9.2",
-		"matthiasnoback/symfony-dependency-injection-test": "2.3.0",
-		"phpunit/phpunit": "6.5.5",
-		"satooshi/php-coveralls": "2.0.0"
+		"consistence/coding-standard": "3.5",
+		"jakub-onderka/php-parallel-lint": "1.0.0",
+		"matthiasnoback/symfony-dependency-injection-test": "3.0.0",
+		"php-coveralls/php-coveralls": "2.1.0",
+		"phpunit/phpunit": "7.4.4",
+		"squizlabs/php_codesniffer": "3.3.2"
 	},
 	"autoload": {
 		"psr-4": { "Mhujer\\JmsSerializer\\Uuid\\SymfonyBundle\\": [ "src" ] },
diff --git a/phpunit.xml.dist b/phpunit.xml.dist
index 79ee404..587cde3 100644
--- a/phpunit.xml.dist
+++ b/phpunit.xml.dist
@@ -2,12 +2,12 @@
 
 <phpunit
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-    xsi:noNamespaceSchemaLocation="http://schema.phpunit.de/6.5/phpunit.xsd"
+    xsi:noNamespaceSchemaLocation="vendor/phpunit/phpunit/phpunit.xsd"
     bootstrap="vendor/autoload.php"
-    colors="true"
+    failOnRisky="true"
+    verbose="true"
     beStrictAboutChangesToGlobalState="true"
     beStrictAboutOutputDuringTests="true"
-    beStrictAboutTodoAnnotatedTests="true"
     >
 
     <testsuites>
diff --git a/src/DependencyInjection/MhujerJmsSerializerUuidExtension.php b/src/DependencyInjection/MhujerJmsSerializerUuidExtension.php
index de1f5f5..1974250 100644
--- a/src/DependencyInjection/MhujerJmsSerializerUuidExtension.php
+++ b/src/DependencyInjection/MhujerJmsSerializerUuidExtension.php
@@ -17,16 +17,13 @@ class MhujerJmsSerializerUuidExtension extends \Symfony\Component\HttpKernel\Dep
 	 * @param mixed[][] $configs
 	 * @param \Symfony\Component\DependencyInjection\ContainerBuilder $container
 	 */
-	public function load(array $configs, ContainerBuilder $container)
+	public function load(array $configs, ContainerBuilder $container): void
 	{
 		$loader = new YamlFileLoader($container, new FileLocator(__DIR__ . '/config'));
 		$loader->load('services.yml');
 	}
 
-	/**
-	 * @return string
-	 */
-	public function getAlias()
+	public function getAlias(): string
 	{
 		return self::ALIAS;
 	}
diff --git a/tests/DependencyInjection/MhujerJmsSerializerUuidExtensionTest.php b/tests/DependencyInjection/MhujerJmsSerializerUuidExtensionTest.php
index 90eaa69..13e83d2 100644
--- a/tests/DependencyInjection/MhujerJmsSerializerUuidExtensionTest.php
+++ b/tests/DependencyInjection/MhujerJmsSerializerUuidExtensionTest.php
@@ -12,14 +12,14 @@ class MhujerJmsSerializerUuidExtensionTest extends \Matthias\SymfonyDependencyIn
 	/**
 	 * @return \Symfony\Component\DependencyInjection\Extension\ExtensionInterface[]
 	 */
-	protected function getContainerExtensions()
+	protected function getContainerExtensions(): array
 	{
 		return [
 			new MhujerJmsSerializerUuidExtension(),
 		];
 	}
 
-	public function testRegisterSerializerHandler()
+	public function testRegisterSerializerHandler(): void
 	{
 		$this->load();