diff --git a/docarray/array/mixins/setitem.py b/docarray/array/mixins/setitem.py
index 18832893567..ab25815239a 100644
--- a/docarray/array/mixins/setitem.py
+++ b/docarray/array/mixins/setitem.py
@@ -65,7 +65,7 @@ def __setitem__(
     ):
         from docarray.helper import check_root_id
 
-        if self._is_subindex:
+        if getattr(self, '_is_subindex', None):
             check_root_id(self, value)
 
         self._update_subindices_set(index, value)
diff --git a/docarray/array/storage/base/seqlike.py b/docarray/array/storage/base/seqlike.py
index ce89b82a3bf..e5c250cdc8d 100644
--- a/docarray/array/storage/base/seqlike.py
+++ b/docarray/array/storage/base/seqlike.py
@@ -75,7 +75,7 @@ def extend(self, values: Iterable['Document'], **kwargs) -> None:
 
         from docarray.helper import check_root_id
 
-        if self._is_subindex:
+        if getattr(self, '_is_subindex', None):
             check_root_id(self, values)
 
         self._extend(values, **kwargs)