diff --git a/umap/static/umap/js/modules/schema.js b/umap/static/umap/js/modules/schema.js
index 9602628f..74856308 100644
--- a/umap/static/umap/js/modules/schema.js
+++ b/umap/static/umap/js/modules/schema.js
@@ -99,26 +99,26 @@ export const SCHEMA = {
   description: {
     type: 'Text',
     impacts: ['ui'],
-    belongsTo: ['map', 'datalayer'],
+    belongsTo: ['map', 'datalayer', 'feature'],
     label: translate('description'),
     helpEntries: 'textFormatting',
   },
   displayOnLoad: {
     type: Boolean,
     impacts: [],
-    belongsTo: ['datalayer'], // XXX ?
+    belongsTo: ['datalayer'],
   },
   displayPopupFooter: {
     type: Boolean,
     impacts: ['ui'],
-    belongsTo: ['map'], // XXX ?
+    belongsTo: ['map'],
     label: translate('Do you want to display popup footer?'),
     default: false,
   },
   easing: {
     type: Boolean,
     impacts: [],
-    belongsTo: ['feature'], // XXX ?
+    belongsTo: ['map', 'datalayer', 'feature'],
     default: false,
   },
   editinosmControl: {
@@ -140,7 +140,7 @@ export const SCHEMA = {
   facetKey: {
     type: String,
     impacts: ['ui'],
-    belongsTo: ['datalayer'],
+    belongsTo: ['map', 'datalayer'],
   },
   fill: {
     type: Boolean,
@@ -174,12 +174,12 @@ export const SCHEMA = {
   filterKey: {
     type: String,
     impacts: [],
-    belongsTo: ['map', 'datalayer', 'feature'], // XXX ?
+    belongsTo: ['map', 'datalayer', 'feature'],
   },
   fromZoom: {
     type: Number,
     impacts: [], // not needed
-    belongsTo: ['map'], // XXX ?
+    belongsTo: ['map', 'datalayer'],
     label: translate('From zoom'),
     helpText: translate('Optional.'),
   },
@@ -232,7 +232,7 @@ export const SCHEMA = {
   inCaption: {
     type: Boolean,
     impacts: ['ui'],
-    belongsTo: [], // XXX ?
+    belongsTo: ['datalayer'],
   },
   interactive: {
     type: Boolean,
@@ -268,7 +268,7 @@ export const SCHEMA = {
   labelKey: {
     type: String,
     impacts: ['data'],
-    belongsTo: ['map', 'datalayer', 'feature'], // XXX ?
+    belongsTo: ['map', 'datalayer', 'feature'],
     helpEntries: 'labelKey',
     placeholder: translate('Default: name'),
     label: translate('Label key'),
@@ -277,7 +277,7 @@ export const SCHEMA = {
   licence: {
     type: String,
     impacts: ['ui'],
-    belongsTo: ['map', 'datalayer'], // XXX ?
+    belongsTo: ['map', 'datalayer'],
     label: translate('licence'),
   },
   limitBounds: {
@@ -354,7 +354,7 @@ export const SCHEMA = {
   outlink: {
     type: String,
     impacts: ['data'],
-    belongsTo: ['feature'],
+    belongsTo: ['map', 'datalayer', 'feature'],
     label: translate('Link to…'),
     helpEntries: 'outlink',
     placeholder: 'http://...',
@@ -363,7 +363,7 @@ export const SCHEMA = {
   outlinkTarget: {
     type: String,
     impacts: ['data'],
-    belongsTo: ['feature'],
+    belongsTo: ['map', 'datalayer', 'feature'],
     label: translate('Open link in…'),
     inheritable: true,
     default: 'blank',
@@ -405,7 +405,7 @@ export const SCHEMA = {
   popupShape: {
     type: String,
     impacts: [], // not needed
-    belongsTo: ['map', 'datalayer', 'feature'], // XXX ?
+    belongsTo: ['map', 'datalayer', 'feature'],
     label: translate('Popup shape'),
     inheritable: true,
     choices: [
@@ -418,7 +418,7 @@ export const SCHEMA = {
   popupTemplate: {
     type: String,
     impacts: [], // not needed
-    belongsTo: ['map', 'datalayer', 'feature'], // XXX ?
+    belongsTo: ['map', 'datalayer', 'feature'],
     label: translate('Popup content style'),
     inheritable: true,
     choices: [
@@ -480,7 +480,7 @@ export const SCHEMA = {
   slugKey: {
     type: String,
     impacts: [],
-    belongsTo: ['map', 'datalayer', 'feature'], // XXX ?
+    belongsTo: ['map', 'datalayer', 'feature'],
   },
   smoothFactor: {
     type: Number,
@@ -538,19 +538,19 @@ export const SCHEMA = {
   toZoom: {
     type: Number,
     impacts: [], // not needed
-    belongsTo: ['map'],
+    belongsTo: ['map', 'datalayer'],
     label: translate('To zoom'),
     helpText: translate('Optional.'),
   },
   type: {
     type: 'String',
     impacts: ['data'],
-    belongsTo: [], // XXX ?
+    belongsTo: ['datalayer'],
   },
   weight: {
     type: Number,
     impacts: ['data'],
-    belongsTo: ['feature'], // XXX ?,
+    belongsTo: ['map', 'datalayer', 'feature'],
     min: 1,
     max: 20,
     step: 1,
@@ -574,10 +574,15 @@ export const SCHEMA = {
   zoomTo: {
     type: Number,
     impacts: [], // not need to update the view
-    belongsTo: ['map'],
+    belongsTo: ['map', 'datalayer', 'feature'],
     placeholder: translate('Inherit'),
     helpEntries: 'zoomTo',
     label: translate('Default zoom level'),
     inheritable: true,
   },
+  _latlng: {
+    type: Object,
+    impacts: ['data'],
+    belongsTo: ['feature'],
+  },
 }
diff --git a/umap/static/umap/js/modules/sync/updaters.js b/umap/static/umap/js/modules/sync/updaters.js
index c9e7e627..080cdf72 100644
--- a/umap/static/umap/js/modules/sync/updaters.js
+++ b/umap/static/umap/js/modules/sync/updaters.js
@@ -1,3 +1,5 @@
+import { propertyBelongsTo } from '../utils.js'
+
 /**
  * This file contains the updaters: classes that are able to convert messages
  * received from another party (or the server) to changes on the map.
@@ -31,9 +33,16 @@ class BaseUpdater {
     return this.map.defaultEditDataLayer()
   }
 
-  applyMessage(message) {
-    let { verb } = message
-    return this[verb](message)
+  applyMessage(payload) {
+    let { verb, subject } = payload
+
+    if (verb == 'update') {
+      if (!propertyBelongsTo(payload.key, subject)) {
+        console.error('Invalid message received', payload)
+        return // Do not apply the message
+      }
+    }
+    return this[verb](payload)
   }
 }
 
diff --git a/umap/static/umap/js/modules/sync/websocket.js b/umap/static/umap/js/modules/sync/websocket.js
index 87540168..e575bed6 100644
--- a/umap/static/umap/js/modules/sync/websocket.js
+++ b/umap/static/umap/js/modules/sync/websocket.js
@@ -9,7 +9,6 @@ export class WebSocketTransport {
   }
 
   onMessage(wsMessage) {
-    // XXX validate incoming data.
     this.receiver.dispatch(JSON.parse(wsMessage.data))
   }
 
diff --git a/umap/static/umap/js/modules/utils.js b/umap/static/umap/js/modules/utils.js
index eca2c44e..7f5a213b 100644
--- a/umap/static/umap/js/modules/utils.js
+++ b/umap/static/umap/js/modules/utils.js
@@ -30,7 +30,8 @@ export function checkId(string) {
  *
  * Return an array of unique impacts.
  *
- * @param {fields} list[fields]
+ * @param {fields}  list[fields]
+ * @param object schema object. If ommited, global U.SCHEMA will be used.
  * @returns Array[string]
  */
 export function getImpactsFromSchema(fields, schema) {
@@ -53,6 +54,31 @@ export function getImpactsFromSchema(fields, schema) {
   return Array.from(impacted)
 }
 
+/**
+ * Checks the given property belongs to the given subject, according to the schema.
+ *
+ * @param srtring property
+ * @param string subject
+ * @param object schema object. If ommited, global U.SCHEMA will be used.
+ * @returns Bool
+ */
+export function propertyBelongsTo(property, subject, schema) {
+  schema = schema || U.SCHEMA
+  if (subject === 'feature') {
+    property = property.replace('properties.', '').replace('_umap_options.', '')
+  }
+  property = property.replace('options.', '')
+  console.log(property)
+  const splits = property.split('.')
+  const nested = splits.length > 1
+  if (nested) property = splits[0]
+  if (!Object.keys(schema).includes(property)) return false
+  if (nested) {
+    if (schema[property].type !== Object) return false
+  }
+  return schema[property].belongsTo.includes(subject)
+}
+
 /**
  * Import DOM purify, and initialize it.
  *
diff --git a/umap/static/umap/unittests/utils.js b/umap/static/umap/unittests/utils.js
index 99b9c8a4..cb6e8d23 100644
--- a/umap/static/umap/unittests/utils.js
+++ b/umap/static/umap/unittests/utils.js
@@ -623,7 +623,76 @@ describe('Utils', function () {
       assert.deepEqual(getImpactsFromSchema(['foo', 'bar', 'baz'], schema), ['A', 'B'])
     })
   })
-  describe('parseNaiveDate', () => {
+
+  describe('#propertyBelongsTo', () => {
+    it('should return false on unexisting property', function () {
+      let schema = {}
+      assert.deepEqual(Utils.propertyBelongsTo('foo', 'map', schema), false)
+    })
+    it('should return false if subject is not listed', function () {
+      let schema = {
+        foo: { belongsTo: ['feature'] },
+      }
+      assert.deepEqual(Utils.propertyBelongsTo('foo', 'map', schema), false)
+    })
+    it('should return true if subject is listed', function () {
+      let schema = {
+        foo: { belongsTo: ['map'] },
+      }
+      assert.deepEqual(Utils.propertyBelongsTo('foo', 'map', schema), true)
+    })
+    it('should remove the `options.` prefix before checking', function () {
+      let schema = {
+        foo: { belongsTo: ['map'] },
+      }
+      assert.deepEqual(Utils.propertyBelongsTo('options.foo', 'map', schema), true)
+    })
+
+    it('Accepts setting properties on objects', function () {
+      let schema = {
+        foo: {
+          type: Object,
+          belongsTo: ['map'],
+        },
+      }
+      assert.deepEqual(Utils.propertyBelongsTo('options.foo.name', 'map', schema), true)
+    })
+
+    it('Rejects setting properties on non-objects', function () {
+      let schema = {
+        foo: {
+          type: String,
+          belongsTo: ['map'],
+        },
+      }
+      assert.deepEqual(
+        Utils.propertyBelongsTo('options.foo.name', 'map', schema),
+        false
+      )
+    })
+
+    it('when subject = feature, should filter the `properties.`', function () {
+      let schema = {
+        foo: { belongsTo: ['feature'] },
+      }
+      assert.deepEqual(
+        Utils.propertyBelongsTo('properties.foo', 'feature', schema),
+        true
+      )
+    })
+
+    it('On features, should filter the `_umap_options.`', function () {
+      let schema = {
+        foo: { belongsTo: ['feature'] },
+      }
+      assert.deepEqual(
+        Utils.propertyBelongsTo('properties._umap_options.foo', 'feature', schema),
+        true
+      )
+    })
+  })
+
+  describe('#parseNaiveDate', () => {
     it('should parse a date', () => {
       assert.equal(
         Utils.parseNaiveDate('2024/03/04').toISOString(),