diff --git a/webseite/classes/SubjectData.php b/webseite/classes/SubjectData.php
index d891011..7e2cfa0 100644
--- a/webseite/classes/SubjectData.php
+++ b/webseite/classes/SubjectData.php
@@ -49,6 +49,11 @@ class SubjectData
 
         $subjectDirectory = "config/subjects";
         $subjectNames = scandir($subjectDirectory);
+
+        usort($subjectNames, function ($a, $b) {
+            return strcmp($a, $b);
+        });
+
         foreach ($subjectNames as $subjectName) {
             if ($subjectName == "." || $subjectName == "..") {
                 continue;
@@ -62,10 +67,6 @@ class SubjectData
             $result[$subjectData->id] = $subjectData;
         }
 
-        usort($result, function ($a, $b) {
-            return strcmp($a->displayName, $b->displayName);
-        });
-
         return $result;
     }
 
diff --git a/webseite/classes/TopicData.php b/webseite/classes/TopicData.php
index 9213984..42b983d 100644
--- a/webseite/classes/TopicData.php
+++ b/webseite/classes/TopicData.php
@@ -54,6 +54,11 @@ class TopicData
 
         $topicDirectory = "config/subjects/$subjectId/topics";
         $topicNames = scandir($topicDirectory);
+
+        usort($topicNames, function ($a, $b) {
+            return strcmp($a, $b);
+        });
+
         foreach ($topicNames as $topicName) {
             if ($topicName == "." || $topicName == "..") {
                 continue;
@@ -66,10 +71,6 @@ class TopicData
             $result[$topicData->id] = $topicData;
         }
 
-        usort($result, function ($a, $b) {
-            return strcmp($a->displayName, $b->displayName);
-        });
-
         return $result;
     }