diff --git a/src/models/dhbw-rapla-changes/changes/changes.service.ts b/src/models/dhbw-rapla-changes/changes/changes.service.ts
index b58ace1..54c38bd 100644
--- a/src/models/dhbw-rapla-changes/changes/changes.service.ts
+++ b/src/models/dhbw-rapla-changes/changes/changes.service.ts
@@ -25,6 +25,10 @@ export const getChanges = async (course: string, week: string): Promise<Event[]>
             relevantEventIds.push(row.entry_id);
         });
 
+        if (relevantEventIds.length < 1) {
+            return [];
+        }
+
         let rows = await conn.query('SELECT c.change_id, c.entry_id, c.change_timestamp, c.isDeleted, c.new_summary, c.new_description, c.new_start, c.new_last_modified, c.new_end, c.new_created, c.new_location, c.new_organizer, c.new_categories, e.uid FROM rapla_changes c LEFT OUTER JOIN rapla_entries e ON c.entry_id = e.entry_id WHERE c.entry_id IN (?) ORDER BY c.change_id', [relevantEventIds]);
 
         let eventsMap = new Map();