diff --git a/server/parser/untis.js b/server/parser/untis.js
index 73fb949..bc3fbef 100644
--- a/server/parser/untis.js
+++ b/server/parser/untis.js
@@ -62,7 +62,7 @@ export function parseSubstitutionPlan(html) {
     const lessons = rawLesson.match(/\d+/g).map(Number);
     for (const lesson of lessons) {
       rowData.lesson = lesson;
-      data.push(rowData);
+      data.push({ ...rowData });
     }
   });