diff --git a/detectron2/data/datasets/pascal_voc.py b/detectron2/data/datasets/pascal_voc.py
index dbbf82cb96..46f8536ad2 100644
--- a/detectron2/data/datasets/pascal_voc.py
+++ b/detectron2/data/datasets/pascal_voc.py
@@ -32,7 +32,7 @@ def load_voc_instances(dirname: str, split: str, class_names: Union[List[str], T
         class_names: list or tuple of class names
     """
     with PathManager.open(os.path.join(dirname, "ImageSets", "Main", split + ".txt")) as f:
-        fileids = np.loadtxt(f, dtype=np.str)
+        fileids = np.loadtxt(f, dtype=str)
 
     # Needs to read many small annotation files. Makes sense at local
     annotation_dirname = PathManager.get_local_path(os.path.join(dirname, "Annotations/"))