diff --git a/ChangeLog-8.5.md b/ChangeLog-8.5.md
index d0b3413b7f1..ca6f31dc41c 100644
--- a/ChangeLog-8.5.md
+++ b/ChangeLog-8.5.md
@@ -7,6 +7,7 @@ All notable changes of the PHPUnit 8.5 release series are documented in this fil
 ### Fixed
 
 * [#4535](https://github.com/sebastianbergmann/phpunit/issues/4535): `getMockFromWsdl()` does not handle methods that do not have parameters correctly
+* [#4572](https://github.com/sebastianbergmann/phpunit/issues/4572): Schema validation does not work with `%xx` sequences in path to `phpunit.xsd`
 
 ## [8.5.13] - 2020-12-01
 
diff --git a/src/Util/Configuration.php b/src/Util/Configuration.php
index 10ad144b7b3..85838e52fc3 100644
--- a/src/Util/Configuration.php
+++ b/src/Util/Configuration.php
@@ -909,7 +909,7 @@ private function validateConfigurationAgainstSchema(): void
             $xsdFilename = __PHPUNIT_PHAR_ROOT__ . '/phpunit.xsd';
         }
 
-        $this->document->schemaValidate($xsdFilename);
+        $this->document->schemaValidateSource(\file_get_contents($xsdFilename));
         $this->errors = \libxml_get_errors();
         \libxml_clear_errors();
         \libxml_use_internal_errors($original);