diff --git a/umap/tests/test_datalayer.py b/umap/tests/test_datalayer.py
index 47bd63f7c..bb29c3d51 100644
--- a/umap/tests/test_datalayer.py
+++ b/umap/tests/test_datalayer.py
@@ -1,4 +1,3 @@
-import tempfile
 from pathlib import Path
 
 import pytest
diff --git a/umap/tests/test_datalayer_views.py b/umap/tests/test_datalayer_views.py
index 19c875ca9..9578ff530 100644
--- a/umap/tests/test_datalayer_views.py
+++ b/umap/tests/test_datalayer_views.py
@@ -1,6 +1,8 @@
 import json
 from copy import deepcopy
+from datetime import datetime, timedelta
 from pathlib import Path
+from unittest import mock
 from uuid import uuid4
 
 import pytest
@@ -621,3 +623,17 @@ def test_optimistic_merge_conflicting_change_raises(
     modified_datalayer = DataLayer.objects.get(pk=datalayer.pk)
     merged_features = json.load(modified_datalayer.geojson)["features"]
     assert merged_features == client1_data["features"]
+
+
+def test_saving_datalayer_should_change_map_last_modified(
+    client, datalayer, map, post_data
+):
+    with mock.patch("django.utils.timezone.now") as mocked:
+        mocked.return_value = datetime.utcnow() - timedelta(days=8)
+        map.save()  # Change last_modified to past
+    old_modified_at = map.modified_at.date()
+    url = reverse("datalayer_update", args=(map.pk, datalayer.pk))
+    client.login(username=map.owner.username, password="123123")
+    response = client.post(url, post_data, follow=True)
+    assert response.status_code == 200
+    assert Map.objects.get(pk=map.pk).modified_at.date() != old_modified_at
diff --git a/umap/views.py b/umap/views.py
index 08de5a7a3..8183b1c3c 100644
--- a/umap/views.py
+++ b/umap/views.py
@@ -1293,6 +1293,7 @@ def post(self, request, *args, **kwargs):
 
     def form_valid(self, form):
         self.object = form.save()
+        self.object.map.save(update_fields=["modified_at"])
         data = {**self.object.metadata(self.request)}
         if self.request.session.get("needs_reload"):
             data["geojson"] = json.loads(self.object.geojson.read().decode())