diff --git a/addons/web/static/src/js/fields/relational_fields.js b/addons/web/static/src/js/fields/relational_fields.js
index 39c66abbfab..5a9b847bb8e 100644
--- a/addons/web/static/src/js/fields/relational_fields.js
+++ b/addons/web/static/src/js/fields/relational_fields.js
@@ -2826,6 +2826,9 @@ var FieldMany2ManyCheckBoxes = AbstractField.extend({
     specialData: "_fetchSpecialRelation",
     supportedFieldTypes: ['many2many'],
     isQuickEditable: true,
+    // set an arbitrary high limit to ensure that all data returned by the server
+    // are processed by the BasicModel (otherwise it would be 40)
+    limit: 100000,
     init: function () {
         this._super.apply(this, arguments);
         this.m2mValues = this.record.specialData[this.name];
diff --git a/addons/web/static/tests/fields/relational_fields_tests.js b/addons/web/static/tests/fields/relational_fields_tests.js
index e0327cfeb6d..880a6e95409 100644
--- a/addons/web/static/tests/fields/relational_fields_tests.js
+++ b/addons/web/static/tests/fields/relational_fields_tests.js
@@ -2534,6 +2534,56 @@ QUnit.module('relational_fields', {
         form.destroy();
     });
 
+    QUnit.test('widget many2many_checkboxes with 40+ values', async function (assert) {
+        // 40 is the default limit for x2many fields. However, the many2many_checkboxes is a
+        // special field that fetches its data through the fetchSpecialData mechanism, and it
+        // uses the name_search server-side limit of 100. This test comes with a fix for a bug
+        // that occurred when the user (un)selected a checkbox that wasn't in the 40 first checkboxes,
+        // because the piece of data corresponding to that checkbox hadn't been processed by the
+        // BasicModel, whereas the code handling the change assumed it had.
+        assert.expect(3);
+
+        const records = [];
+        for (let id = 1; id <= 90; id++) {
+            records.push({
+                id,
+                display_name: `type ${id}`,
+                color: id % 7,
+            });
+        }
+        this.data.partner_type.records = records;
+        this.data.partner.records[0].timmy = records.map((r) => r.id);
+
+        const form = await createView({
+            View: FormView,
+            model: 'partner',
+            data: this.data,
+            arch: '<form><field name="timmy" widget="many2many_checkboxes"/></form>',
+            res_id: 1,
+            async mockRPC(route, args) {
+                if (args.method === 'write') {
+                    const expectedIds = records.map((r) => r.id);
+                    expectedIds.pop();
+                    assert.deepEqual(args.args[1].timmy, [[6, false, expectedIds]]);
+                }
+                return this._super(...arguments);
+            },
+            viewOptions: {
+                mode: 'edit',
+            },
+        });
+
+        assert.containsN(form, '.o_field_widget[name=timmy] input[type=checkbox]:checked', 90);
+
+        // toggle the last value
+        await testUtils.dom.click(form.$('.o_field_widget[name=timmy] input[type=checkbox]:last'));
+        assert.notOk(form.$('.o_field_widget[name=timmy] input[type=checkbox]:last').is(':checked'));
+
+        await testUtils.form.clickSave(form);
+
+        form.destroy();
+    });
+
     QUnit.module('FieldMany2ManyBinaryMultiFiles');
 
     QUnit.test('widget many2many_binary', async function (assert) {