diff --git a/phpunit.xml b/phpunit.xml
index c62bfbf..120443e 100644
--- a/phpunit.xml
+++ b/phpunit.xml
@@ -1,18 +1,20 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <!-- http://phpunit.de/manual/4.1/en/appendixes.configuration.html -->
-<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/9.3/phpunit.xsd" backupGlobals="false" bootstrap="./vendor/autoload.php" colors="true" convertErrorsToExceptions="true" convertNoticesToExceptions="true" convertWarningsToExceptions="true">
-    <coverage>
-        <include>
-            <directory suffix=".php">./src</directory>
-        </include>
-        <report>
-            <html outputDirectory="./test/unit/_html" />
-        </report>
-    </coverage>
-    <testsuites>
-        <testsuite name="Unit">
-            <directory>./test/unit</directory>
-        </testsuite>
-    </testsuites>
-    <logging/>
+<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/10.5/phpunit.xsd" backupGlobals="false" bootstrap="./vendor/autoload.php" colors="true" cacheDirectory=".phpunit.cache">
+  <coverage>
+    <report>
+      <html outputDirectory="./test/unit/_html"/>
+    </report>
+  </coverage>
+  <testsuites>
+    <testsuite name="Unit">
+      <directory>./test/unit</directory>
+    </testsuite>
+  </testsuites>
+  <logging/>
+  <source>
+    <include>
+      <directory suffix=".php">./src</directory>
+    </include>
+  </source>
 </phpunit>
