diff --git a/webseite/classes/SubjectData.php b/webseite/classes/SubjectData.php
index fc6fa72..d891011 100644
--- a/webseite/classes/SubjectData.php
+++ b/webseite/classes/SubjectData.php
@@ -62,6 +62,10 @@ 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 6954a24..9213984 100644
--- a/webseite/classes/TopicData.php
+++ b/webseite/classes/TopicData.php
@@ -66,6 +66,10 @@ class TopicData
             $result[$topicData->id] = $topicData;
         }
 
+        usort($result, function ($a, $b) {
+            return strcmp($a->displayName, $b->displayName);
+        });
+
         return $result;
     }