diff --git a/CHANGES.md b/CHANGES.md
index 63a28b8ab06..1d6ec9600c8 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -6,6 +6,7 @@ Changes
 
 ### Unreleased
 
+* 2024-05-11 - Improvement: Smart menu "locations" must be filled with a value, resolves #404
 * 2024-05-10 - Bugfix: Do not show empty smart menus to users, resolves #405
 * 2024-05-09 - Bugfix: Smart menu menubar overlaid course index, resolves #607
 * 2024-04-27 - Improvement: Add navigation to policy overview page, resolves #633
diff --git a/classes/form/smartmenu_edit_form.php b/classes/form/smartmenu_edit_form.php
index 58cc884a133..becdd8de8c2 100644
--- a/classes/form/smartmenu_edit_form.php
+++ b/classes/form/smartmenu_edit_form.php
@@ -77,6 +77,7 @@ public function definition() {
                 $locationtypes);
         $mform->addHelpButton('location', 'smartmenusmenulocation', 'theme_boost_union');
         $location->setMultiple(true);
+        $mform->addRule('location', get_string('required'), 'required');
 
         // Add mode as select element.
         $modeoptions = [
@@ -320,6 +321,11 @@ public function validation($data, $files) {
             }
         }
 
+        // Validate the smart menu location is filled.
+        if (empty($data['location'])) {
+            $errors['location'] = get_string('required');
+        }
+
         // Return errors.
         return $errors;
     }
diff --git a/tests/behat/theme_boost_union_smartmenusettings_menus_management.feature b/tests/behat/theme_boost_union_smartmenusettings_menus_management.feature
index 6593dc9f996..fa88708a0b4 100644
--- a/tests/behat/theme_boost_union_smartmenusettings_menus_management.feature
+++ b/tests/behat/theme_boost_union_smartmenusettings_menus_management.feature
@@ -62,6 +62,7 @@ Feature: Configuring the theme_boost_union plugin on the "Smart menus" page, man
     And I click on "Create menu" "button"
     And I set the following fields to these values:
       | Title | Links |
+      | Menu location(s) | Main |
     And I click on "Save and return" "button"
     And I should see "Links" in the "smartmenus" "table"
     And ".action-delete" "css_element" should exist in the "smartmenus" "table"
@@ -109,17 +110,20 @@ Feature: Configuring the theme_boost_union plugin on the "Smart menus" page, man
     And I click on ".action-show" "css_element" in the "Links" "table_row"
     Then I should see smart menu "Links" in location "Main, Menu, User, Bottom"
 
+  @javascript
   Scenario: Smartmenus: Menus: Management - Move an existing smart menu up and down
     When I log in as "admin"
     And I navigate to smart menus
     And I click on "Create menu" "button"
     And I set the following fields to these values:
       | Title | Enrolled courses |
+      | Menu location(s) | Main  |
     And I click on "Save and return" "button"
     And I should see "Enrolled courses" in the "smartmenus" "table"
     And I click on "Create menu" "button"
     And I set the following fields to these values:
       | Title | Completed courses |
+      | Menu location(s) | Main   |
     And I click on "Save and return" "button"
     And I should see "Completed courses" in the "smartmenus" "table"
     And "Enrolled courses" "table_row" should appear before "Completed courses" "table_row"
@@ -127,3 +131,20 @@ Feature: Configuring the theme_boost_union plugin on the "Smart menus" page, man
     Then "Enrolled courses" "table_row" should appear after "Completed courses" "table_row"
     And I click on ".sort-smartmenus-up-action" "css_element" in the "Enrolled courses" "table_row"
     And "Enrolled courses" "table_row" should appear before "Completed courses" "table_row"
+
+  @javascript
+  Scenario: Smartmenus: Menus: Management - Make sure that location field is filled
+    When I log in as "admin"
+    And I navigate to smart menus
+    And I click on "Create menu" "button"
+    And I set the following fields to these values:
+      | Title            | Links     |
+    And I click on "Save and return" "button"
+    Then I should see "Required" in the "#fitem_id_location" "css_element"
+    And I set the field "Menu location(s)" to "Main"
+    And I click on "Save and return" "button"
+    Then I should see "Links" in the "smartmenus" "table"
+    And I set "Links" smart menu items with the following fields to these values:
+      | Title          | Info    |
+      | Menu item type | Heading |
+    Then I should see smart menu "Links" in location "Main"