diff --git a/composer.json b/composer.json
index b217cbf..b56fdf7 100644
--- a/composer.json
+++ b/composer.json
@@ -19,7 +19,9 @@
         "phpunit/phpunit": "~4.0"
     },
     "autoload": {
-        "psr-0": {"DebugBar": "src/"}
+        "psr-4": {
+            "DebugBar\\": "src/DebugBar/"
+        }
     },
     "suggest": {
         "kriswallsmith/assetic": "The best way to manage assets",