diff --git a/README.md b/README.md
index e617e69..b90844b 100644
--- a/README.md
+++ b/README.md
@@ -12,7 +12,7 @@ validity of the resulting config node tree, this library provides a PHPUnit test
 
 Using Composer:
 
-    php composer.phar require matthiasnoback/symfony-config-test 0.*
+    php composer.phar require --dev matthiasnoback/symfony-config-test 0.*
 
 ## Usage