diff --git a/tests/unit/framework/YiiBaseTest.php b/tests/unit/framework/YiiBaseTest.php
index bc31c0a..e256b2b 100644
--- a/tests/unit/framework/YiiBaseTest.php
+++ b/tests/unit/framework/YiiBaseTest.php
@@ -45,6 +45,9 @@ class YiiBaseTest extends TestCase
 		Yii::setAlias('@yii', null);
 		$this->assertFalse(Yii::getAlias('@yii', false));
 		$this->assertEquals('/yii/gii/file', Yii::getAlias('@yii/gii/file'));
+
+		Yii::setAlias('@some/alias', '/www');
+		$this->assertEquals('/www', Yii::getAlias('@some/alias'));
 	}
 
 	public function testGetVersion()
diff --git a/yii/YiiBase.php b/yii/YiiBase.php
index ce421d4..ad48e52 100644
--- a/yii/YiiBase.php
+++ b/yii/YiiBase.php
@@ -287,7 +287,11 @@ class YiiBase
 		if ($path !== null) {
 			$path = strncmp($path, '@', 1) ? rtrim($path, '\\/') : static::getAlias($path);
 			if (!isset(self::$aliases[$root])) {
-				self::$aliases[$root] = $path;
+				if ($pos === false) {
+					self::$aliases[$root] = $path;
+				} else {
+					self::$aliases[$root] = array($alias => $path);
+				}
 			} elseif (is_string(self::$aliases[$root])) {
 				if ($pos === false) {
 					self::$aliases[$root] = $path;