diff --git a/webseite/classes/TopicData.php b/webseite/classes/TopicData.php
index fde0cc2..af0192c 100644
--- a/webseite/classes/TopicData.php
+++ b/webseite/classes/TopicData.php
@@ -487,6 +487,11 @@ class TopicData
 
     public function setId(string $id): void
     {
+        rename(
+            Config::getTopicDirectory($this->getSubjectId(), $this->getId()),
+            Config::getTopicDirectory($this->getSubjectId(), $id)
+        );
+
         $this->id = $id;
     }
 
@@ -497,6 +502,11 @@ class TopicData
 
     public function setSubjectId(string $subjectId): void
     {
+        rename(
+            Config::getTopicDirectory($this->getSubjectId(), $this->getId()),
+            Config::getTopicDirectory($subjectId, $this->getId())
+        );
+
         $this->subjectId = $subjectId;
     }
 
diff --git a/webseite/topicEditor.php b/webseite/topicEditor.php
index b3669cd..135eb37 100644
--- a/webseite/topicEditor.php
+++ b/webseite/topicEditor.php
@@ -191,9 +191,10 @@ if ($_SERVER['REQUEST_METHOD'] == 'POST') {
         $article = preg_replace("/^[ \r\n\t]*<p><p>/", "<p>", $article);
         $article = preg_replace("#</p></p>[ \r\n\t]*$#", "</p>", $article);
 
-        if (isset($allSubjects[$_POST['subjectId']]->getTopics()[$_POST['id']])) {
-            $newTopic = $allSubjects[$_POST['subjectId']]->getTopics()[$_POST['id']];
+        if (isset($allSubjects[$_POST['oldSubjectId']]->getTopics()[$_POST['oldTopicId']])) {
+            $newTopic = $allSubjects[$_POST['oldSubjectId']]->getTopics()[$_POST['oldTopicId']];
 
+            $newTopic->setId($_POST['id']);
             $newTopic->setDisplayName($_POST['displayName']);
             $newTopic->setSubjectId($_POST['subjectId']);
             $newTopic->setDescription($_POST['description']);
@@ -289,6 +290,8 @@ if ($_SERVER['REQUEST_METHOD'] == 'POST') {
                            class="w-full px-4 py-3 border rounded-lg focus:outline-none focus:ring-2 focus:ring-blue-500 text-lg enabled:hover:border-gray-400"
                            required
                            value="<?php echo $defaultValues['id']; ?>">
+
+                    <input type="hidden" name="oldTopicId" value="<?php echo $defaultValues['id']; ?>">
                 </div>
 
                 <div>
@@ -312,6 +315,8 @@ if ($_SERVER['REQUEST_METHOD'] == 'POST') {
                                 <path d="M7 10l5 5 5-5H7z"/>
                             </svg>
                         </div>
+
+                        <input type="hidden" name="oldSubjectId" value="<?php echo $defaultValues['subjectId']; ?>">
                     </div>
                 </div>