diff --git a/addons/web/static/src/views/calendar/calendar_model.js b/addons/web/static/src/views/calendar/calendar_model.js
index 17a7f08f6d3..891cbdc1aaa 100644
--- a/addons/web/static/src/views/calendar/calendar_model.js
+++ b/addons/web/static/src/views/calendar/calendar_model.js
@@ -45,6 +45,10 @@ export class CalendarModel extends Model {
                     ? deserializeDateTime(params.context.initial_date)
                     : luxon.DateTime.local();
         }
+        // Prevent picking a scale that is not supported by the view
+        if (!this.meta.scales.includes(this.meta.scale)) {
+            this.meta.scale = this.meta.scales[0];
+        }
         const data = { ...this.data };
         await this.keepLast.add(this.updateData(data));
         this.data = data;
diff --git a/addons/web/static/tests/views/calendar/calendar_view_tests.js b/addons/web/static/tests/views/calendar/calendar_view_tests.js
index 042d7cac229..4085b374af4 100644
--- a/addons/web/static/tests/views/calendar/calendar_view_tests.js
+++ b/addons/web/static/tests/views/calendar/calendar_view_tests.js
@@ -3934,4 +3934,21 @@ QUnit.module("Views", ({ beforeEach }) => {
         // test would fail here if we don't ignore readonly modifier
         assert.containsOnce(target, ".o_cw_popover");
     });
+
+    QUnit.test("can not select invalid scale from datepicker", async (assert) => {
+        await makeView({
+            type: "calendar",
+            resModel: "event",
+            serverData,
+            arch: `
+                <calendar date_start="start" date_stop="stop" all_day="allday" mode="month" scales="month,year">
+                    <field name="name" attrs="{'readonly': [['unknown_field', '=', 42]]}" />
+                </calendar>
+            `,
+        });
+
+        await click(target, ".ui-datepicker-today");
+        // test would fail here if we went to week mode
+        assert.containsOnce(target, ".fc-dayGridMonth-view");
+    });
 });