diff --git a/composer.json b/composer.json
index 39560144b..e2bea24a6 100644
--- a/composer.json
+++ b/composer.json
@@ -77,7 +77,7 @@
     "grimmlink/qtip2": "3.0.3"
   },
   "require-dev": {
-    "phpunit/phpunit": "4.8 - 6.5.5",
+    "phpunit/phpunit": "4.8 - 7.5.10",
     "umpirsky/twig-gettext-extractor": "1.3.*",
     "symfony/dom-crawler": "3.4.3",
     "mockery/mockery": "1.0"
diff --git a/phpunit.xml b/phpunit.xml
index d0f06f5cc..8e6fc2a7b 100644
--- a/phpunit.xml
+++ b/phpunit.xml
@@ -1,6 +1,6 @@
 <phpunit colors="true" bootstrap="tests/bootstrap.php" processIsolation="true">
   <logging>
-    <log type="coverage-html" target="./report" charset="UTF-8" highlight="false" lowUpperBound="35" highLowerBound="70"/>  
+    <log type="coverage-html" target="./report" lowUpperBound="35" highLowerBound="70"/>  
     <log type="coverage-clover" target="build/logs/clover.xml"/>
   </logging>
   <testsuites>
@@ -9,13 +9,13 @@
     </testsuite>
   </testsuites>
   <filter>
-    <blacklist>
-      <directory>vendor</directory>
-    </blacklist>
     <whitelist processUncoveredFilesFromWhitelist="true">
         <directory suffix=".php">controller</directory>
         <directory suffix=".php">model</directory>
         <directory suffix=".php">model/sparql</directory>
+        <exclude>
+          <directory>vendor</directory>
+        </exclude>
     </whitelist>
   </filter>
 </phpunit>
diff --git a/tests/VocabularyConfigTest.php b/tests/VocabularyConfigTest.php
index 989176eb3..1916ce5c0 100644
--- a/tests/VocabularyConfigTest.php
+++ b/tests/VocabularyConfigTest.php
@@ -417,7 +417,7 @@ public function testGetMainConceptSchemeURI() {
     $vocab = $this->model->getVocabulary('testdiff');
     $this->assertEquals('http://www.skosmos.skos/testdiff#conceptscheme' , $vocab->getConfig()->getMainConceptSchemeURI());
     $vocab = $this->model->getVocabulary('test');
-    $this->assertNull(null , $vocab->getConfig()->getMainConceptSchemeURI());
+    $this->assertNull($vocab->getConfig()->getMainConceptSchemeURI());
   }
 
   /**