diff --git a/composer.json b/composer.json
index 1b8afa8..da573a6 100644
--- a/composer.json
+++ b/composer.json
@@ -5,8 +5,9 @@
 	"homepage": "http://simplehtmldom.sourceforge.net/",
 	"type": "library",
 	"version": "1.5",
-	"require":{
-		"php":">=5.2.4"
+	"require": {
+		"php": ">=5.2.4",
+		"ext-mbstring": "*"
 	},
 	"authors": [
 		{
@@ -16,7 +17,7 @@
 		}
 	],
 	"autoload": {
-		"classmap":["simple_html_dom.php"],
+		"classmap": ["simple_html_dom.php"],
 		"files": ["simple_html_dom.php"]
 	}
-}
\ No newline at end of file
+}