diff --git a/umap/static/umap/js/modules/data/layer.js b/umap/static/umap/js/modules/data/layer.js
index fba926b8..f999b96b 100644
--- a/umap/static/umap/js/modules/data/layer.js
+++ b/umap/static/umap/js/modules/data/layer.js
@@ -269,13 +269,11 @@ export class DataLayer extends ServerStored {
   }
 
   clear() {
-    this.layer.clearLayers()
-    this._features = {}
-    this._index = Array()
-    if (this._geojson) {
-      this.backupData()
-      this._geojson = null
+    this.sync.startBatch()
+    for (const feature of Object.values(this._features)) {
+      feature.del()
     }
+    this.sync.commitBatch()
     this.dataChanged()
   }
 
diff --git a/umap/static/umap/js/modules/sync/undo.js b/umap/static/umap/js/modules/sync/undo.js
index d16263cc..954b6955 100644
--- a/umap/static/umap/js/modules/sync/undo.js
+++ b/umap/static/umap/js/modules/sync/undo.js
@@ -43,7 +43,11 @@ export class UndoManager {
 
   copyOperation(stage, redo) {
     const operation = Utils.CopyJSON(stage.operation)
-    operation.value = redo ? stage.newValue : stage.oldValue
+    const value = redo ? stage.newValue : stage.oldValue
+    operation.value = value
+    if (['delete', 'upsert'].includes(operation.verb)) {
+      operation.verb = value === null || value === undefined ? 'delete' : 'upsert'
+    }
     return operation
   }
 
@@ -73,18 +77,15 @@ export class UndoManager {
     switch (operation.verb) {
       case 'update':
         updater.update(operation)
-        this._syncEngine._send(operation)
         break
       case 'delete':
+        updater.delete(operation)
+        break
       case 'upsert':
-        if (operation.value === null || operation.value === undefined) {
-          updater.delete(operation)
-        } else {
-          updater.upsert(operation)
-        }
-        this._syncEngine._send(operation)
+        updater.upsert(operation)
         break
     }
+    this._syncEngine._send(operation)
   }
 
   _getUpdater(subject, metadata) {
diff --git a/umap/tests/base.py b/umap/tests/base.py
index 0e862cb4..59e64a76 100644
--- a/umap/tests/base.py
+++ b/umap/tests/base.py
@@ -18,6 +18,7 @@ DATALAYER_DATA = {
     "features": [
         {
             "type": "Feature",
+            "id": "ExNTQ",
             "geometry": {
                 "type": "Point",
                 "coordinates": [14.68896484375, 48.55297816440071],
diff --git a/umap/tests/integration/test_websocket_sync.py b/umap/tests/integration/test_websocket_sync.py
index 40db583e..7dd256cf 100644
--- a/umap/tests/integration/test_websocket_sync.py
+++ b/umap/tests/integration/test_websocket_sync.py
@@ -659,3 +659,33 @@ def test_should_sync_line_on_escape(new_page, asgi_live_server, tilelayer):
 
     expect(peerA.locator("path")).to_have_count(1)
     expect(peerB.locator("path")).to_have_count(1)
+
+
+@pytest.mark.xdist_group(name="websockets")
+def test_should_sync_datalayer_clear(
+    new_page, asgi_live_server, tilelayer, map, datalayer
+):
+    map.settings["properties"]["syncEnabled"] = True
+    map.edit_status = Map.ANONYMOUS
+    map.save()
+
+    # Create two tabs
+    peerA = new_page("Page A")
+    peerA.goto(f"{asgi_live_server.url}{map.get_absolute_url()}?edit")
+    peerB = new_page("Page B")
+    peerB.goto(f"{asgi_live_server.url}{map.get_absolute_url()}?edit")
+    expect(peerA.locator(".leaflet-marker-icon")).to_have_count(1)
+    expect(peerB.locator(".leaflet-marker-icon")).to_have_count(1)
+
+    # Clear layer in peer A
+    peerA.get_by_role("button", name="Manage layers").click()
+    peerA.get_by_role("button", name="Edit", exact=True).click()
+    peerA.locator("summary").filter(has_text="Advanced actions").click()
+    peerA.get_by_role("button", name="Empty").click()
+    expect(peerA.locator(".leaflet-marker-icon")).to_have_count(0)
+    expect(peerB.locator(".leaflet-marker-icon")).to_have_count(0)
+
+    # Undo in peer A
+    peerA.get_by_role("button", name="Undo").click()
+    expect(peerA.locator(".leaflet-marker-icon")).to_have_count(1)
+    expect(peerB.locator(".leaflet-marker-icon")).to_have_count(1)