diff --git a/tabellio/searchform/form.py b/tabellio/searchform/form.py
index 53e136c..29b7066 100644
--- a/tabellio/searchform/form.py
+++ b/tabellio/searchform/form.py
@@ -259,7 +259,7 @@ def possible_topics(context):
     catalog = getToolByName(context, 'portal_catalog')
     topics = tabellio.config.utils.get_topics_dict()
     terms = []
-    for key, value in topics.items():
+    for key, value in sorted(topics.items()):
         topic_id = key
         topic_str = value[0]
         terms.append(SimpleVocabulary.createTerm(topic_id, topic_id, topic_str))