diff --git a/lib/Doctrine/Migration/Builder.php b/lib/Doctrine/Migration/Builder.php
index 0e7ba5960..d322d8f5a 100644
--- a/lib/Doctrine/Migration/Builder.php
+++ b/lib/Doctrine/Migration/Builder.php
@@ -40,7 +40,7 @@ class Doctrine_Migration_Builder
      *
      * @var string
      */
-    private $migrationsPath = '';
+    private $_migrationsPath = '';
 
     /**
      * suffix
@@ -49,16 +49,16 @@ class Doctrine_Migration_Builder
      *
      * @var string $suffix
      */
-    private $suffix = '.class.php';
+    private $_suffix = '.class.php';
 
     /**
      * tpl
      *
      * Class template used for writing classes
      *
-     * @var $tpl
+     * @var $_tpl
      */
-    private static $tpl;
+    private static $_tpl;
 
     /**
      * __construct
@@ -71,7 +71,7 @@ class Doctrine_Migration_Builder
             $this->setMigrationsPath($migrationsPath);
         }
         
-        $this->loadTemplate();
+        $this->_loadTemplate();
     }
 
     /**
@@ -84,7 +84,7 @@ class Doctrine_Migration_Builder
     {
         Doctrine_Lib::makeDirectories($path);
 
-        $this->migrationsPath = $path;
+        $this->_migrationsPath = $path;
     }
 
     /**
@@ -94,7 +94,7 @@ class Doctrine_Migration_Builder
      */
     public function getMigrationsPath()
     {
-        return $this->migrationsPath;
+        return $this->_migrationsPath;
     }
 
     /**
@@ -104,13 +104,13 @@ class Doctrine_Migration_Builder
      *
      * @return void
      */
-    protected function loadTemplate() 
+    protected function _loadTemplate() 
     {
-        if (isset(self::$tpl)) {
+        if (isset(self::$_tpl)) {
             return;
         }
 
-        self::$tpl =<<<END
+        self::$_tpl =<<<END
 /**
  * This class has been auto-generated by the Doctrine ORM Framework
  */
@@ -267,7 +267,7 @@ END;
             $migration = new Doctrine_Migration($this->getMigrationsPath());
             $next = (string) $migration->getNextVersion();
             
-            $fileName = str_repeat('0', (3 - strlen($next))) . $next . '_' . Doctrine::tableize($className) . $this->suffix;
+            $fileName = str_repeat('0', (3 - strlen($next))) . $next . '_' . Doctrine::tableize($className) . $this->_suffix;
             
             $class = $this->buildMigrationClass($className, $fileName, $options, $up, $down);
             
@@ -288,7 +288,7 @@ END;
         
         $content  = '<?php' . PHP_EOL;
         
-        $content .= sprintf(self::$tpl, $className,
+        $content .= sprintf(self::$_tpl, $className,
                                        $extends,
                                        $up,
                                        $down);