diff --git a/dpdata/system.py b/dpdata/system.py
index 2bb28ad6..00172602 100644
--- a/dpdata/system.py
+++ b/dpdata/system.py
@@ -1049,7 +1049,7 @@ def remove_atom_names(self, atom_names: str | list[str]):
             atom_idx = self.data["atom_types"] == idx
             removed_atom_idx.append(atom_idx)
         picked_atom_idx = ~np.any(removed_atom_idx, axis=0)
-        assert not isinstance(picked_atom_idx, np.bool)
+        assert not isinstance(picked_atom_idx, np.bool_)
         new_sys = self.pick_atom_idx(picked_atom_idx)
         # let's remove atom_names
         # firstly, rearrange atom_names and put these atom_names in the end