diff --git a/src/Test/MakerTestCase.php b/src/Test/MakerTestCase.php
index 7691f405a..be541ecec 100644
--- a/src/Test/MakerTestCase.php
+++ b/src/Test/MakerTestCase.php
@@ -109,7 +109,7 @@ private function hasRequiredDependencyVersions(MakerTestDetails $testDetails, Ma
 
         $installedPackages = json_decode($testEnv->readFile('vendor/composer/installed.json'), true);
         $packageVersions = [];
-        foreach ($installedPackages as $installedPackage) {
+        foreach ($installedPackages['packages'] ?? $installedPackages as $installedPackage) {
             $packageVersions[$installedPackage['name']] = $installedPackage['version_normalized'];
         }