diff --git a/framework/yii/base/Application.php b/framework/yii/base/Application.php
index 2bd3455..da2ad6b 100644
--- a/framework/yii/base/Application.php
+++ b/framework/yii/base/Application.php
@@ -54,6 +54,13 @@ abstract class Application extends Module
 	 * @event ActionEvent an event raised after executing a controller action.
 	 */
 	const EVENT_AFTER_ACTION = 'afterAction';
+
+	/**
+	 * @var string the namespace that controller classes are in. If not set,
+	 * it will use the "app\controllers" namespace.
+	 */
+	public $controllerNamespace = 'app\\controllers';
+
 	/**
 	 * @var string the application name.
 	 */
@@ -221,6 +228,18 @@ abstract class Application extends Module
 	}
 
 	/**
+	 * Sets the root directory of the applicaition and the @app alias.
+	 * This method can only be invoked at the beginning of the constructor.
+	 * @param string $path the root directory of the application.
+	 * @throws InvalidParamException if the directory does not exist.
+	 */
+	public function setBasePath($path)
+	{
+		parent::setBasePath($path);
+		Yii::setAlias('@app', $this->getBasePath());
+	}
+
+	/**
 	 * Runs the application.
 	 * This is the main entrance of an application.
 	 * @return integer the exit status (0 means normal, non-zero values mean abnormal)
diff --git a/framework/yii/base/Module.php b/framework/yii/base/Module.php
index ee3949b..1fdf5ee 100644
--- a/framework/yii/base/Module.php
+++ b/framework/yii/base/Module.php
@@ -83,7 +83,6 @@ abstract class Module extends Component
 	 * it will use the "controllers" sub-namespace under the namespace of this module.
 	 * For example, if the namespace of this module is "foo\bar", then the default
 	 * controller namespace would be "foo\bar\controllers".
-	 * If the module is an application, it will default to "app\controllers".
 	 */
 	public $controllerNamespace;
 	/**
@@ -167,20 +166,16 @@ abstract class Module extends Component
 	/**
 	 * Initializes the module.
 	 * This method is called after the module is created and initialized with property values
-	 * given in configuration. The default implement will create a path alias using the module [[id]]
+	 * given in configuration. The default implementation will create a path alias using the module [[id]]
 	 * and then call [[preloadComponents()]] to load components that are declared in [[preload]].
 	 */
 	public function init()
 	{
 		$this->preloadComponents();
 		if ($this->controllerNamespace === null) {
-			if ($this instanceof Application) {
-				$this->controllerNamespace = 'app\\controllers';
-			} else {
-				$class = get_class($this);
-				if (($pos = strrpos($class, '\\')) !== false) {
-					$this->controllerNamespace = substr($class, 0, $pos) . '\\controllers';
-				}
+			$class = get_class($this);
+			if (($pos = strrpos($class, '\\')) !== false) {
+				$this->controllerNamespace = substr($class, 0, $pos) . '\\controllers';
 			}
 		}
 	}
@@ -221,9 +216,6 @@ abstract class Module extends Component
 		$p = realpath($path);
 		if ($p !== false && is_dir($p)) {
 			$this->_basePath = $p;
-			if ($this instanceof Application) {
-				Yii::setAlias('@app', $p);
-			}
 		} else {
 			throw new InvalidParamException("The directory does not exist: $path");
 		}