diff --git a/modules/openapi-generator/src/main/resources/php-slim4-server/phpunit.xml.mustache b/modules/openapi-generator/src/main/resources/php-slim4-server/phpunit.xml.mustache
index c8e5d27ca2a7..026da14ad2e7 100644
--- a/modules/openapi-generator/src/main/resources/php-slim4-server/phpunit.xml.mustache
+++ b/modules/openapi-generator/src/main/resources/php-slim4-server/phpunit.xml.mustache
@@ -1,32 +1,22 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<phpunit
-    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-    xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/4.8/phpunit.xsd"
-    bootstrap="./vendor/autoload.php"
-    colors="true"
-    convertErrorsToExceptions="true"
-    convertNoticesToExceptions="true"
-    convertWarningsToExceptions="true"
-    beStrictAboutTestsThatDoNotTestAnything="false"
-    stopOnFailure="false"
->
-    <testsuites>
-        <testsuite name="Apis">
-            <directory>{{apiTestPath}}</directory>
-        </testsuite>
-        <testsuite name="Models">
-            <file>./{{testBasePath}}/BaseModelTest.php</file>
-            <directory>{{modelTestPath}}</directory>
-        </testsuite>
-    </testsuites>
-    <filter>
-        <whitelist processUncoveredFilesFromWhitelist="true">
-            <directory suffix=".php">{{apiSrcPath}}</directory>
-            <file>./{{srcBasePath}}/BaseModel.php</file>
-            <directory suffix=".php">{{modelSrcPath}}</directory>
-        </whitelist>
-    </filter>
-    <php>
-        <ini name="error_reporting" value="E_ALL" />
-    </php>
+<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/9.3/phpunit.xsd" bootstrap="./vendor/autoload.php" colors="true" convertErrorsToExceptions="true" convertNoticesToExceptions="true" convertWarningsToExceptions="true" beStrictAboutTestsThatDoNotTestAnything="false" stopOnFailure="false">
+  <coverage processUncoveredFiles="true">
+    <include>
+      <directory suffix=".php">{{apiSrcPath}}</directory>
+      <file>./{{srcBasePath}}/BaseModel.php</file>
+      <directory suffix=".php">{{modelSrcPath}}</directory>
+    </include>
+  </coverage>
+  <testsuites>
+    <testsuite name="Apis">
+      <directory>{{apiTestPath}}</directory>
+    </testsuite>
+    <testsuite name="Models">
+      <file>./{{testBasePath}}/BaseModelTest.php</file>
+      <directory>{{modelTestPath}}</directory>
+    </testsuite>
+  </testsuites>
+  <php>
+    <ini name="error_reporting" value="E_ALL"/>
+  </php>
 </phpunit>
diff --git a/samples/server/petstore/php-slim4/phpunit.xml.dist b/samples/server/petstore/php-slim4/phpunit.xml.dist
index 1e245113f4b1..d5f76a3c6422 100644
--- a/samples/server/petstore/php-slim4/phpunit.xml.dist
+++ b/samples/server/petstore/php-slim4/phpunit.xml.dist
@@ -1,32 +1,22 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<phpunit
-    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-    xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/4.8/phpunit.xsd"
-    bootstrap="./vendor/autoload.php"
-    colors="true"
-    convertErrorsToExceptions="true"
-    convertNoticesToExceptions="true"
-    convertWarningsToExceptions="true"
-    beStrictAboutTestsThatDoNotTestAnything="false"
-    stopOnFailure="false"
->
-    <testsuites>
-        <testsuite name="Apis">
-            <directory>./tests/Api</directory>
-        </testsuite>
-        <testsuite name="Models">
-            <file>./tests/BaseModelTest.php</file>
-            <directory>./tests/Model</directory>
-        </testsuite>
-    </testsuites>
-    <filter>
-        <whitelist processUncoveredFilesFromWhitelist="true">
-            <directory suffix=".php">./lib/Api</directory>
-            <file>./lib/BaseModel.php</file>
-            <directory suffix=".php">./lib/Model</directory>
-        </whitelist>
-    </filter>
-    <php>
-        <ini name="error_reporting" value="E_ALL" />
-    </php>
+<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/9.3/phpunit.xsd" bootstrap="./vendor/autoload.php" colors="true" convertErrorsToExceptions="true" convertNoticesToExceptions="true" convertWarningsToExceptions="true" beStrictAboutTestsThatDoNotTestAnything="false" stopOnFailure="false">
+  <coverage processUncoveredFiles="true">
+    <include>
+      <directory suffix=".php">./lib/Api</directory>
+      <file>./lib/BaseModel.php</file>
+      <directory suffix=".php">./lib/Model</directory>
+    </include>
+  </coverage>
+  <testsuites>
+    <testsuite name="Apis">
+      <directory>./tests/Api</directory>
+    </testsuite>
+    <testsuite name="Models">
+      <file>./tests/BaseModelTest.php</file>
+      <directory>./tests/Model</directory>
+    </testsuite>
+  </testsuites>
+  <php>
+    <ini name="error_reporting" value="E_ALL"/>
+  </php>
 </phpunit>