diff --git a/framework/yii/web/Request.php b/framework/yii/web/Request.php
index b8c2a592c7..f2298e6a4e 100644
--- a/framework/yii/web/Request.php
+++ b/framework/yii/web/Request.php
@@ -584,7 +584,9 @@ class Request extends \yii\base\Request
 			throw new InvalidConfigException('Unable to determine the path info of the current request.');
 		}
 
-		if ($pathInfo[0] === '/') {
+		if ($pathInfo === '/') {
+			$pathInfo = '';
+		} else if ($pathInfo[0] === '/') {
 			$pathInfo = substr($pathInfo, 1);
 		}