diff --git a/tests/Composer/Test/Autoload/Fixtures/autoload_functions.php b/tests/Composer/Test/Autoload/Fixtures/autoload_functions.php
index 6c304b7d6..668c8f880 100644
--- a/tests/Composer/Test/Autoload/Fixtures/autoload_functions.php
+++ b/tests/Composer/Test/Autoload/Fixtures/autoload_functions.php
@@ -3,8 +3,21 @@
 // autoload.php @generated by Composer
 
 if (PHP_VERSION_ID < 50600) {
-    echo 'Composer 2.3.0 dropped support for autoloading on PHP <5.6 and you are running '.PHP_VERSION.', please upgrade PHP or use Composer 2.2 LTS via "composer self-update --2.2". Aborting.'.PHP_EOL;
-    exit(1);
+    if (!headers_sent()) {
+        header('HTTP/1.1 500 Internal Server Error');
+    }
+    $err = 'Composer 2.3.0 dropped support for autoloading on PHP <5.6 and you are running '.PHP_VERSION.', please upgrade PHP or use Composer 2.2 LTS via "composer self-update --2.2". Aborting.'.PHP_EOL;
+    if (!ini_get('display_errors')) {
+        if (PHP_SAPI === 'cli' || PHP_SAPI === 'phpdbg') {
+            fwrite(STDERR, $err);
+        } elseif (!headers_sent()) {
+            echo $err;
+        }
+    }
+    trigger_error(
+        $err,
+        E_USER_ERROR
+    );
 }
 
 require_once __DIR__ . '/composer/autoload_real.php';
diff --git a/tests/Composer/Test/Autoload/Fixtures/autoload_functions_by_dependency.php b/tests/Composer/Test/Autoload/Fixtures/autoload_functions_by_dependency.php
index ce7a2f223..776a152ea 100644
--- a/tests/Composer/Test/Autoload/Fixtures/autoload_functions_by_dependency.php
+++ b/tests/Composer/Test/Autoload/Fixtures/autoload_functions_by_dependency.php
@@ -3,8 +3,21 @@
 // autoload.php @generated by Composer
 
 if (PHP_VERSION_ID < 50600) {
-    echo 'Composer 2.3.0 dropped support for autoloading on PHP <5.6 and you are running '.PHP_VERSION.', please upgrade PHP or use Composer 2.2 LTS via "composer self-update --2.2". Aborting.'.PHP_EOL;
-    exit(1);
+    if (!headers_sent()) {
+        header('HTTP/1.1 500 Internal Server Error');
+    }
+    $err = 'Composer 2.3.0 dropped support for autoloading on PHP <5.6 and you are running '.PHP_VERSION.', please upgrade PHP or use Composer 2.2 LTS via "composer self-update --2.2". Aborting.'.PHP_EOL;
+    if (!ini_get('display_errors')) {
+        if (PHP_SAPI === 'cli' || PHP_SAPI === 'phpdbg') {
+            fwrite(STDERR, $err);
+        } elseif (!headers_sent()) {
+            echo $err;
+        }
+    }
+    trigger_error(
+        $err,
+        E_USER_ERROR
+    );
 }
 
 require_once __DIR__ . '/composer/autoload_real.php';
diff --git a/tests/Composer/Test/Autoload/Fixtures/autoload_target_dir.php b/tests/Composer/Test/Autoload/Fixtures/autoload_target_dir.php
index 52c462cd6..cc1ee89ff 100644
--- a/tests/Composer/Test/Autoload/Fixtures/autoload_target_dir.php
+++ b/tests/Composer/Test/Autoload/Fixtures/autoload_target_dir.php
@@ -3,8 +3,21 @@
 // autoload.php @generated by Composer
 
 if (PHP_VERSION_ID < 50600) {
-    echo 'Composer 2.3.0 dropped support for autoloading on PHP <5.6 and you are running '.PHP_VERSION.', please upgrade PHP or use Composer 2.2 LTS via "composer self-update --2.2". Aborting.'.PHP_EOL;
-    exit(1);
+    if (!headers_sent()) {
+        header('HTTP/1.1 500 Internal Server Error');
+    }
+    $err = 'Composer 2.3.0 dropped support for autoloading on PHP <5.6 and you are running '.PHP_VERSION.', please upgrade PHP or use Composer 2.2 LTS via "composer self-update --2.2". Aborting.'.PHP_EOL;
+    if (!ini_get('display_errors')) {
+        if (PHP_SAPI === 'cli' || PHP_SAPI === 'phpdbg') {
+            fwrite(STDERR, $err);
+        } elseif (!headers_sent()) {
+            echo $err;
+        }
+    }
+    trigger_error(
+        $err,
+        E_USER_ERROR
+    );
 }
 
 require_once __DIR__ . '/composer/autoload_real.php';