diff --git a/composer.json b/composer.json
index f18e043..33cf8a5 100644
--- a/composer.json
+++ b/composer.json
@@ -1,7 +1,7 @@
 {
     "name": "deblan/fos-rest-behavior",
     "type": "propel-behavior",
-	"licence": "MIT",
+    "licence": "MIT",
     "authors": [
         {
             "name": "Simon Vieille",
@@ -14,11 +14,11 @@
         }
     },
     "require": {
-		"jms/serializer-bundle": "~1.1"
-	},
+        "jms/serializer-bundle": "~1.1"
+    },
     "extra": {
-		"name": "fos_rest",
-		"class": "src/Deblan/Propel/Behavior/FOSRestBehavior.php"
+        "name": "fos_rest",
+        "class": "src/Deblan/Propel/Behavior/FOSRestBehavior.php"
     }
 }
 
diff --git a/src/Deblan/Propel/Behavior/FOSRestBehavior.php b/src/Deblan/Propel/Behavior/FOSRestBehavior.php
index cff8cdd..4985769 100644
--- a/src/Deblan/Propel/Behavior/FOSRestBehavior.php
+++ b/src/Deblan/Propel/Behavior/FOSRestBehavior.php
@@ -65,7 +65,7 @@ class FOSRestBehavior extends Behavior
             }
         }
 
-        return implode(', ', $data);
+        return sprintf('{%s}', implode(', ', $data));
     }
 
     /**