diff --git a/packages/common/decorators/core/inject.decorator.ts b/packages/common/decorators/core/inject.decorator.ts
index 471c77c08ac..8eba6c15025 100644
--- a/packages/common/decorators/core/inject.decorator.ts
+++ b/packages/common/decorators/core/inject.decorator.ts
@@ -34,7 +34,7 @@ import { isUndefined } from '../../utils/shared.utils';
  * @publicApi
  */
 export function Inject<T = any>(token?: T) {
-  return (target: object, key: string | symbol, index?: number) => {
+  return (target: object, key: string | symbol | undefined, index?: number) => {
     const type = token || Reflect.getMetadata('design:type', target, key);
 
     if (!isUndefined(index)) {
diff --git a/packages/common/decorators/core/optional.decorator.ts b/packages/common/decorators/core/optional.decorator.ts
index 49d80eec1d5..69f88ceafd3 100644
--- a/packages/common/decorators/core/optional.decorator.ts
+++ b/packages/common/decorators/core/optional.decorator.ts
@@ -18,7 +18,7 @@ import { isUndefined } from '../../utils/shared.utils';
  * @publicApi
  */
 export function Optional() {
-  return (target: object, key: string | symbol, index?: number) => {
+  return (target: object, key: string | symbol | undefined, index?: number) => {
     if (!isUndefined(index)) {
       const args = Reflect.getMetadata(OPTIONAL_DEPS_METADATA, target) || [];
       Reflect.defineMetadata(OPTIONAL_DEPS_METADATA, [...args, index], target);