diff --git a/package.json b/package.json
index b7232e7..3491af9 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "depents",
-  "version": "0.0.3",
+  "version": "0.0.4",
   "description": "depents is a typescript dependency injector",
   "main": "./js/Index.js",
   "repository": {
diff --git a/src/Decorator.ts b/src/Decorator.ts
index b6ecbc3..14aaf53 100644
--- a/src/Decorator.ts
+++ b/src/Decorator.ts
@@ -12,7 +12,7 @@ export function Singleton(config?: {
 
   return (clazz: Type<any>) => {
     Injector['singletonDefinitions'].push({
-      initializationPriority: config ?. initializationPriority,
+      initializationPriority: (config && config.initializationPriority) ? config.initializationPriority :  0,
       ctor: clazz
     })