diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index d87f1847..a816af3a 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -6,6 +6,9 @@ on:
 
 name: "CI"
 
+env:
+  COMPOSER_ROOT_VERSION: "5.0-dev"
+
 permissions:
   contents: read
 
diff --git a/composer.json b/composer.json
index 3e28e19b..a53ecba4 100644
--- a/composer.json
+++ b/composer.json
@@ -35,7 +35,7 @@
         "ext-mbstring": "*"
     },
     "require-dev": {
-        "phpunit/phpunit": "^10.0"
+        "phpunit/phpunit": "^10.3"
     },
     "config": {
         "platform": {
diff --git a/tests/MockObjectComparatorTest.php b/tests/MockObjectComparatorTest.php
index e1c07778..c11fe91a 100644
--- a/tests/MockObjectComparatorTest.php
+++ b/tests/MockObjectComparatorTest.php
@@ -12,7 +12,7 @@
 use PHPUnit\Framework\Attributes\CoversClass;
 use PHPUnit\Framework\Attributes\DataProvider;
 use PHPUnit\Framework\Attributes\UsesClass;
-use PHPUnit\Framework\MockObject\Generator;
+use PHPUnit\Framework\MockObject\Generator\Generator;
 use PHPUnit\Framework\MockObject\MockObject;
 use PHPUnit\Framework\TestCase;
 use stdClass;