diff --git a/addons/web/static/src/js/widgets/date_picker.js b/addons/web/static/src/js/widgets/date_picker.js
index df9601b3a04..90e77aafb41 100644
--- a/addons/web/static/src/js/widgets/date_picker.js
+++ b/addons/web/static/src/js/widgets/date_picker.js
@@ -84,8 +84,8 @@ var DateWidget = Widget.extend({
      * set datetime value
      */
     changeDatetime: function () {
+        var oldValue = this.getValue();
         if (this.isValid()) {
-            var oldValue = this.getValue();
             this._setValueFromUi();
             var newValue = this.getValue();
             var hasChanged = !oldValue !== !newValue;
@@ -102,6 +102,9 @@ var DateWidget = Widget.extend({
                 }
                 this.trigger("datetime_changed");
             }
+        } else {
+            var formattedValue = oldValue ? this._formatClient(oldValue) : null;
+            this.$input.val(formattedValue);
         }
     },
     /**
diff --git a/addons/web/static/tests/fields/basic_fields_tests.js b/addons/web/static/tests/fields/basic_fields_tests.js
index 7fae0f7963a..84a5844b8c0 100644
--- a/addons/web/static/tests/fields/basic_fields_tests.js
+++ b/addons/web/static/tests/fields/basic_fields_tests.js
@@ -2696,8 +2696,32 @@ QUnit.module('basic_fields', {
         form.destroy();
     });
 
-    QUnit.test('date field should remove the date  if the date is not valid', function (assert) {
-        assert.expect(1);
+    QUnit.test('date field: set an invalid date when the field is already set', function (assert) {
+        assert.expect(2);
+
+        var form = createView({
+            View: FormView,
+            model: 'partner',
+            data: this.data,
+            arch: '<form string="Partners"><field name="date"/></form>',
+            res_id: 1,
+            viewOptions: {
+                mode: 'edit',
+            },
+        });
+
+        var $input = form.$('.o_field_widget[name=date] input');
+
+        assert.strictEqual($input.val(), "02/03/2017");
+
+        $input.val('mmmh').trigger('change');
+        assert.strictEqual($input.val(), "02/03/2017", "should have reset the original value");
+
+        form.destroy();
+    });
+
+    QUnit.test('date field: set an invalid date when the field is not set yet', function (assert) {
+        assert.expect(2);
 
         var form = createView({
             View: FormView,
@@ -2705,13 +2729,18 @@ QUnit.module('basic_fields', {
             data: this.data,
             arch: '<form string="Partners"><field name="date"/></form>',
             res_id: 4,
+            viewOptions: {
+                mode: 'edit',
+            },
         });
-        // switch to edit mode
-        form.$buttons.find('.o_form_button_edit').click();
-        // set an invalid date
+
         var $input = form.$('.o_field_widget[name=date] input');
+
+        assert.strictEqual($input.text(), "");
+
         $input.val('mmmh').trigger('change');
         assert.strictEqual($input.text(), "", "The date field should be empty");
+
         form.destroy();
     });