diff --git a/lib/autoload.php b/lib/autoload.php
index 9861c4c24c..1b6f5ac129 100644
--- a/lib/autoload.php
+++ b/lib/autoload.php
@@ -14,7 +14,10 @@ if (PHP_VERSION_ID < 50600) {
             echo $err;
         }
     }
-    throw new RuntimeException($err);
+    trigger_error(
+        $err,
+        E_USER_ERROR
+    );
 }
 
 require_once __DIR__ . '/composer/autoload_real.php';
diff --git a/lib/composer/platform_check.php b/lib/composer/platform_check.php
index f6cf0ea27c..bb733000d3 100644
--- a/lib/composer/platform_check.php
+++ b/lib/composer/platform_check.php
@@ -36,7 +36,8 @@ if ($issues) {
             echo 'Composer detected issues in your platform:' . PHP_EOL.PHP_EOL . str_replace('You are running '.PHP_VERSION.'.', '', implode(PHP_EOL, $issues)) . PHP_EOL.PHP_EOL;
         }
     }
-    throw new \RuntimeException(
-        'Composer detected issues in your platform: ' . implode(' ', $issues)
+    trigger_error(
+        'Composer detected issues in your platform: ' . implode(' ', $issues),
+        E_USER_ERROR
     );
 }