diff --git a/test.py b/test.py
index 028e9e13ac93..177ac2494cab 100644
--- a/test.py
+++ b/test.py
@@ -236,7 +236,7 @@ def test(data,
     parser.add_argument('--merge', action='store_true', help='use Merge NMS')
     parser.add_argument('--verbose', action='store_true', help='report mAP by class')
     opt = parser.parse_args()
-    opt.save_json = opt.save_json or opt.data.endswith('coco.yaml')
+    opt.save_json |= opt.data.endswith('coco.yaml')
     opt.data = check_file(opt.data)  # check file
     print(opt)