diff --git a/umap/tests/test_datalayer_views.py b/umap/tests/test_datalayer_views.py
index e2c4e925..3693725e 100644
--- a/umap/tests/test_datalayer_views.py
+++ b/umap/tests/test_datalayer_views.py
@@ -1,4 +1,5 @@
 import json
+from pathlib import Path
 
 import pytest
 from django.core.files.base import ContentFile
@@ -33,6 +34,17 @@ def test_get(client, settings, datalayer):
     assert j["type"] == "FeatureCollection"
 
 
+def test_gzip_should_be_created_if_accepted(client, datalayer, map, post_data):
+    url = reverse("datalayer_view", args=(datalayer.pk,))
+    response = client.get(url, headers={"ACCEPT_ENCODING": "gzip"})
+    assert response.status_code == 200
+    flat = datalayer.geojson.path
+    gzipped = datalayer.geojson.path + ".gz"
+    assert Path(flat).exists()
+    assert Path(gzipped).exists()
+    assert Path(flat).stat().st_mtime_ns == Path(gzipped).stat().st_mtime_ns
+
+
 def test_update(client, datalayer, map, post_data):
     url = reverse("datalayer_update", args=(map.pk, datalayer.pk))
     client.login(username=map.owner.username, password="123123")
@@ -49,6 +61,7 @@ def test_update(client, datalayer, map, post_data):
     j = json.loads(response.content.decode())
     assert "id" in j
     assert datalayer.pk == j["id"]
+    assert Path(modified_datalayer.geojson.path).exists()
 
 
 def test_should_not_be_possible_to_update_with_wrong_map_id_in_url(
diff --git a/umap/utils.py b/umap/utils.py
index 0890dbfd..29417150 100644
--- a/umap/utils.py
+++ b/umap/utils.py
@@ -112,7 +112,7 @@ def gzip_file(from_path, to_path):
     with open(from_path, "rb") as f_in:
         with gzip.open(to_path, "wb") as f_out:
             f_out.writelines(f_in)
-    os.utime(to_path, (stat.st_mtime, stat.st_mtime))
+    os.utime(to_path, ns=(stat.st_mtime_ns, stat.st_mtime_ns))
 
 
 def is_ajax(request):
diff --git a/umap/views.py b/umap/views.py
index 3459e49e..b79240c5 100644
--- a/umap/views.py
+++ b/umap/views.py
@@ -784,11 +784,28 @@ class GZipMixin(object):
     def path(self):
         return self.object.geojson.path
 
+    @property
+    def gzip_path(self):
+        return Path(f"{self.path}{self.EXT}")
+
     @property
     def last_modified(self):
-        stat = os.stat(self.path)
+        # Prior to 1.3.0 we did not set gzip mtime as geojson mtime,
+        # but we switched from If-Match header to IF-Unmodified-Since
+        # and when users accepts gzip their last modified value is the gzip
+        # (when umap is served by nginx and X-Accel-Redirect)
+        # one, so we need to compare with that value in that case.
+        # cf https://github.com/umap-project/umap/issues/1212
+        path = self.gzip_path if self.accepts_gzip else self.path
+        stat = os.stat(path)
         return http_date(stat.st_mtime)
 
+    @property
+    def accepts_gzip(self):
+        return settings.UMAP_GZIP and re_accepts_gzip.search(
+            self.request.META.get("HTTP_ACCEPT_ENCODING", "")
+        )
+
 
 class DataLayerView(GZipMixin, BaseDetailView):
     model = DataLayer
@@ -797,13 +814,9 @@ class DataLayerView(GZipMixin, BaseDetailView):
         response = None
         path = self.path
         # Generate gzip if needed
-        accepts_gzip = re_accepts_gzip.search(
-            self.request.META.get("HTTP_ACCEPT_ENCODING", "")
-        )
-        if accepts_gzip and settings.UMAP_GZIP:
-            gzip_path = Path(f"{path}{self.EXT}")
-            if not gzip_path.exists():
-                gzip_file(path, gzip_path)
+        if self.accepts_gzip:
+            if not self.gzip_path.exists():
+                gzip_file(path, self.gzip_path)
 
         if getattr(settings, "UMAP_XSENDFILE_HEADER", None):
             response = HttpResponse()