diff --git a/build.xml b/build.xml
index a60e0d6bfea..6532ea8b2e8 100644
--- a/build.xml
+++ b/build.xml
@@ -48,7 +48,6 @@
             <arg value="--no-progress"/>
             <arg value="--no-ansi"/>
             <arg value="--no-suggest"/>
-            <arg value="--optimize-autoloader"/>
             <arg value="--prefer-stable"/>
         </exec>
     </target>
diff --git a/composer.json b/composer.json
index 90bfb29f65a..1726365bf4c 100644
--- a/composer.json
+++ b/composer.json
@@ -53,6 +53,7 @@
         "platform": {
             "php": "5.6.0"
         },
+        "optimize-autoloader": true,
         "sort-packages": true
     },
     "suggest": {