diff --git a/composer.json b/composer.json
index 1b36ed6c..2de0b3a7 100644
--- a/composer.json
+++ b/composer.json
@@ -19,7 +19,7 @@
 		"consistence/coding-standard": "~0.13.0",
 		"jakub-onderka/php-parallel-lint": "^0.9.2",
 		"phing/phing": "^2.16.0",
-		"phpunit/phpunit": "^5.7",
+		"phpunit/phpunit": "^6.3",
 		"slevomat/coding-standard": "^2.0"
 	},
 	"autoload": {
diff --git a/tests/phpunit.xml b/tests/phpunit.xml
index fc7e5723..e2a13abc 100644
--- a/tests/phpunit.xml
+++ b/tests/phpunit.xml
@@ -1,26 +1,26 @@
-<phpunit
-		bootstrap="bootstrap.php"
-		colors="true"
-		backupGlobals="false"
-		backupStaticAttributes="false"
-		beStrictAboutChangesToGlobalState="true"
-		beStrictAboutOutputDuringTests="true"
-		beStrictAboutTestsThatDoNotTestAnything="true"
-		beStrictAboutTodoAnnotatedTests="true"
-		failOnRisky="true"
-		failOnWarning="true"
->
+<?xml version="1.0" encoding="UTF-8"?>
+<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/6.3/phpunit.xsd"
+	bootstrap="bootstrap.php"
+	colors="true"
+	failOnRisky="true"
+	failOnWarning="true"
+	beStrictAboutChangesToGlobalState="true"
+	beStrictAboutCoversAnnotation="true"
+	beStrictAboutOutputDuringTests="true"
+	beStrictAboutTodoAnnotatedTests="true"
+	verbose="false">
+	<testsuite>
+		<directory suffix="Test.php">.</directory>
+	</testsuite>
+
 	<filter>
-		<whitelist>
+		<whitelist processUncoveredFilesFromWhitelist="true">
 			<directory suffix=".php">../src</directory>
 		</whitelist>
 	</filter>
+
 	<logging>
-		<log
-				type="coverage-text"
-				target="php://stdout"
-				showUncoveredFiles="true"
-				showOnlySummary="true"
-		/>
+		<log type="coverage-text" target="php://stdout" showUncoveredFiles="true" showOnlySummary="true"/>
 	</logging>
 </phpunit>