diff --git a/ultralytics/models/yolo/detect/val.py b/ultralytics/models/yolo/detect/val.py
index 5550ec3ec..6650046a8 100644
--- a/ultralytics/models/yolo/detect/val.py
+++ b/ultralytics/models/yolo/detect/val.py
@@ -65,7 +65,7 @@ def preprocess(self, batch):
     def init_metrics(self, model):
         """Initialize evaluation metrics for YOLO."""
         val = self.data.get(self.args.split, "")  # validation path
-        self.is_coco = isinstance(val, str) and "coco" in val and val.endswith(f"{os.sep}val2017.txt")  # is COCO
+        self.is_coco = isinstance(val, str) and "coco" in val and (val.endswith(f"{os.sep}val2017.txt") or val.endswith(f"{os.sep}test-dev2017.txt"))  # is COCO
         self.class_map = converter.coco80_to_coco91_class() if self.is_coco else list(range(1000))
         self.args.save_json |= self.is_coco  # run on final val if training COCO
         self.names = model.names