diff --git a/.kateproject b/.kateproject
index 18da774c..ca3bca28 100644
--- a/.kateproject
+++ b/.kateproject
@@ -1,4 +1,5 @@
 {
+	"name": "lbplanner-plugin",
 	"lspclient": {
 		"servers": {
 			"php" : {
diff --git a/lbplanner/classes/helpers/config_helper.php b/lbplanner/classes/helpers/config_helper.php
index f29417bd..47e7a8e0 100644
--- a/lbplanner/classes/helpers/config_helper.php
+++ b/lbplanner/classes/helpers/config_helper.php
@@ -58,17 +58,13 @@ public static function set_default_active_year() {
     }
 
     /**
-     * Adds a customfield to moodle for each activity where teachers can select GK EK or both.
-     *
-     * Default value is GK.
-     * @throws \coding_exception
-     * @throws \moodle_exception
-     * @throws \coding_exception
+     * Adds a customfield to moodle for each activity where teachers can select GK EK Test or M.
+     * Default value is empty.
      */
     public static function add_customfield(): void {
         // Check if the category is already created and only create it if it doesn't exist.
         // Check if plugin "modcustomfields" is installed and create the category and the custom field.
-        if (!get_config('local_lbplanner', 'categoryid')) {
+        if (self::get_category_id() === -1) {
 
             if (array_key_exists('modcustomfields', core_component::get_plugin_list('local'))) {
 
@@ -100,16 +96,28 @@ public static function add_customfield(): void {
             }
         }
     }
+    /**
+     * Adds a customfield to moodle for each activity where teachers can select GK EK or both.
+     *
+     * @throws \coding_exception
+     * @throws \moodle_exception
+     */
+    public static function remove_customfield(): void {
+        $handler = mod_handler::create();
+        $catcontroller = category_controller::create(self::get_category_id(), null, $handler);
+        $handler->delete_category($catcontroller);
+    }
 
     /**
      * Get the category id from the config
      * @return int the category id if it is set, -1 otherwise
      */
     public static function get_category_id(): int {
-        if (!get_config('local_lbplanner', 'categoryid')) {
+        $catid = get_config('local_lbplanner', 'categoryid');
+        if ($catid === false) {
             return -1;
         } else {
-            return intval(get_config('local_lbplanner', 'categoryid'));
+            return intval($catid);
         }
     }
 }
diff --git a/lbplanner/db/uninstall.php b/lbplanner/db/uninstall.php
new file mode 100644
index 00000000..52003a1e
--- /dev/null
+++ b/lbplanner/db/uninstall.php
@@ -0,0 +1,36 @@
+<?php
+// This file is part of local_lbplanner.
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
+
+/**
+ * Contains some stuff for when the plugin gets uninstalled.
+ * Upgrading the plugin shouldn't trigger this code.
+ *
+ * @package local_lbplanner
+ * @subpackage db
+ * @copyright 2024 NecodeIT
+ * @license https://creativecommons.org/licenses/by-nc-sa/4.0/ CC-BY-NC-SA 4.0 International or later
+ */
+
+use local_lbplanner\helpers\config_helper;
+
+
+/**
+ * Runs when plugin is uninstalled
+ */
+function xmldb_local_lbplanner_uninstall() {
+    config_helper::remove_customfield();
+}
+