diff --git a/tests/test_notes.py b/tests/test_notes.py
index 464fa4e..ef83f31 100644
--- a/tests/test_notes.py
+++ b/tests/test_notes.py
@@ -19,6 +19,7 @@ from thoughtsync.notes import (
     _header_filename,
     _keep_spec,
     _native_spec,
+    _note_markdown,
     _safe_filename,
     _slugify,
     _usec_to_dt,
@@ -533,3 +534,39 @@ def test_the_migration_folds_exactly_like_the_app():
         ("prose\n", "  padded  ", True),
     ]:
         assert module._append_item(body, text, checked) == append_item(body, text, checked)
+
+
+# --- import/export: the body already carries the list ------------------------
+
+
+def test_note_markdown_writes_a_checklist_once():
+    """The export used to append the items after the body. The body IS them now
+    (M304), so the old branch would have doubled every checklist in an export — and
+    doubled it again on the next re-import."""
+    note = Note(
+        display_title="shopping",
+        body="shopping\n\n- [ ] milk\n- [x] eggs",
+        color="default",
+        pinned=False,
+        archived=False,
+    )
+    out = _note_markdown(note, [])
+    assert out.count("- [ ] milk") == 1
+    assert out.count("- [x] eggs") == 1
+    # And in place, under the note's own first line rather than in a block of its own.
+    assert out.rstrip().endswith("shopping\n\n- [ ] milk\n- [x] eggs")
+
+
+def test_native_spec_of_a_current_export_folds_nothing():
+    # Today's export carries no `items` key, because the body has the lines. An empty
+    # list is what stops _insert_note folding them in a second time.
+    assert _native_spec({"body": "a\n\n- [ ] milk"})["items"] == []
+
+
+def test_native_spec_of_a_pre_m304_export_still_carries_its_items():
+    # An export taken BEFORE this milestone has a body with no task lines and a
+    # separate items array. Importing one has to put the checklist back — which is
+    # the same fold the Keep importer does, and the reason _insert_note still accepts
+    # items at all.
+    old = {"body": "shopping", "items": [{"text": "milk", "checked": True}]}
+    assert _native_spec(old)["items"] == [{"text": "milk", "checked": True}]