diff --git a/src/models/face-detection-item.ts b/src/models/face-detection-item.ts
index b3a02655..04a8bc4f 100644
--- a/src/models/face-detection-item.ts
+++ b/src/models/face-detection-item.ts
@@ -28,6 +28,6 @@ export interface FaceDetectionItem {
      * @type {FaceDetection}
      * @memberof FaceDetectionItem
      */
-    'FaceDetection': FaceDetection;
+    'FaceDetection'?: FaceDetection;
 }