diff --git a/package.json b/package.json
index 6fb3990..6f32a89 100644
--- a/package.json
+++ b/package.json
@@ -1,14 +1,14 @@
 {
     "$schema": "https://raw.githubusercontent.com/hullis/squirrel/master/src/schema/package.schema.json",
     "name": "@wendellhu/redi",
-    "version": "0.6.4",
+    "version": "0.6.5",
     "description": "A dependency library for TypeScript and JavaScript, along with a binding for React.",
     "scripts": {
         "test": "vitest --coverage",
         "lint": "eslint --fix 'src/**/*.ts'",
         "lint:prettier": "prettier --write '{src,test}/**/*.{ts,tsx}'",
         "build": "squirrel",
-        "typeCheck": "tsc -p tsconfig.json --noEmit"
+        "typeCheck": "tsc -p tsconfig.check.json --noEmit"
     },
     "exports": {},
     "squirrel": {
diff --git a/src/decorators.ts b/src/decorators.ts
index a66cf60..eb54fad 100644
--- a/src/decorators.ts
+++ b/src/decorators.ts
@@ -103,9 +103,9 @@ export function createIdentifier<T>(id: string): IdentifierDecorator<T> {
         knownIdentifiers.add(id)
     }
 
-    const decorator = function (registerTarget: Ctor<T>, _key: string, index: number): void {
+    const decorator = (<any>function (registerTarget: Ctor<T>, _key: string, index: number): void {
         setDependency(registerTarget, decorator, index)
-    } as IdentifierDecorator<T> // decorator as an identifier
+    }) as IdentifierDecorator<T> // decorator as an identifier
 
     decorator.toString = () => id
     decorator[IdentifierDecoratorSymbol] = true
diff --git a/src/dependencyIdentifier.ts b/src/dependencyIdentifier.ts
index 711e860..2734e8f 100644
--- a/src/dependencyIdentifier.ts
+++ b/src/dependencyIdentifier.ts
@@ -6,15 +6,15 @@ export const IdentifierDecoratorSymbol = Symbol('$$IDENTIFIER_DECORATOR')
 export type IdentifierDecorator<T> = {
     [IdentifierDecoratorSymbol]: true
 
-    /**
-     * decorator
-     */
-    (target: Ctor<T>, key: string, index: number): void
+    // call signature of an decorator
+    (...args: any[]): void
 
     /**
      * beautify console
      */
     toString(): string
+
+    type: T
 }
 
 export type DependencyIdentifier<T> = string | Ctor<T> | ForwardRef<T> | IdentifierDecorator<T>
diff --git a/test/.DS_Store b/test/.DS_Store
new file mode 100644
index 0000000..dcc1cec
Binary files /dev/null and b/test/.DS_Store differ
diff --git a/tsconfig.check.json b/tsconfig.check.json
new file mode 100644
index 0000000..4dea500
--- /dev/null
+++ b/tsconfig.check.json
@@ -0,0 +1,4 @@
+{
+    "extends": "./tsconfig.json",
+    "include": ["src/**/*", "test/**/*"]
+}