diff --git a/src/Composer/Plugin/PluginManager.php b/src/Composer/Plugin/PluginManager.php
index e48f0fd1a..bd5519986 100644
--- a/src/Composer/Plugin/PluginManager.php
+++ b/src/Composer/Plugin/PluginManager.php
@@ -172,9 +172,9 @@ class PluginManager
                 $path = $classLoader->findFile($class);
                 $code = file_get_contents($path);
                 $code = preg_replace('{^((?:final\s+)?(?:\s*))class\s+(\S+)}mi', '$1class $2_composer_tmp'.self::$classCounter, $code);
-                $code = str_replace('__FILE__', "'".str_replace(array('\\', "'"), array('\\\\', "\\'"), $path)."'", $code);
-                $code = str_replace('__DIR__', "'".str_replace(array('\\', "'"), array('\\\\', "\\'"), dirname($path))."'", $code);
-                $code = str_replace('__CLASS__', "'".str_replace(array('\\', "'"), array('\\\\', "\\'"), $class)."'", $code);
+                $code = str_replace('__FILE__', var_export($path, true), $code);
+                $code = str_replace('__DIR__', var_export(dirname($path), true), $code);
+                $code = str_replace('__CLASS__', var_export($class, true), $code);
                 eval('?>'.$code);
                 $class .= '_composer_tmp'.self::$classCounter;
                 self::$classCounter++;