diff --git a/lib/Doctrine/Common/Inflector/Inflector.php b/lib/Doctrine/Common/Inflector/Inflector.php
index 5dddd304..3a951af8 100644
--- a/lib/Doctrine/Common/Inflector/Inflector.php
+++ b/lib/Doctrine/Common/Inflector/Inflector.php
@@ -269,7 +269,7 @@ public static function tableize($word)
      */
     public static function classify($word)
     {
-        return str_replace(" ", "", ucwords(strtr($word, "_-", "  ")));
+        return str_replace(' ', '', ucwords(strtr($word, '_-', '  ')));
     }
 
     /**