diff --git a/umap/static/umap/js/umap.features.js b/umap/static/umap/js/umap.features.js
index 4d3a17a8..740a3d0e 100644
--- a/umap/static/umap/js/umap.features.js
+++ b/umap/static/umap/js/umap.features.js
@@ -608,6 +608,7 @@ U.FeatureMixin = {
       properties.lat = center.lat
       properties.lon = center.lng
       properties.lng = center.lng
+      properties.alt = this._latlng?.alt
       if (typeof this.getMeasure !== 'undefined') {
         properties.measure = this.getMeasure()
       }
diff --git a/umap/tests/integration/test_view_marker.py b/umap/tests/integration/test_view_marker.py
index bc689183..ca06d8dc 100644
--- a/umap/tests/integration/test_view_marker.py
+++ b/umap/tests/integration/test_view_marker.py
@@ -19,7 +19,7 @@ DATALAYER_DATA = {
             },
             "geometry": {
                 "type": "Point",
-                "coordinates": [14.6889, 48.5529],
+                "coordinates": [14.6889, 48.5529, 241],
             },
         },
     ],
@@ -88,6 +88,7 @@ def test_extended_properties_in_popup(live_server, map, page, bootstrap):
     Lang: {lang}
     Lat: {lat}
     Lon: {lon}
+    Alt: {alt}
     Zoom: {zoom}
     Layer: {layer}
     """
@@ -102,5 +103,6 @@ def test_extended_properties_in_popup(live_server, map, page, bootstrap):
     expect(page.get_by_text("Lang: en")).to_be_visible()
     expect(page.get_by_text("Lat: 48.5529")).to_be_visible()
     expect(page.get_by_text("Lon: 14.6889")).to_be_visible()
+    expect(page.get_by_text("Alt: 241")).to_be_visible()
     expect(page.get_by_text("Zoom: 7")).to_be_visible()
     expect(page.get_by_text("Layer: test datalayer")).to_be_visible()