diff --git a/app/api/songs/route.ts b/app/api/songs/route.ts
index 0414638..dd753f4 100644
--- a/app/api/songs/route.ts
+++ b/app/api/songs/route.ts
@@ -457,7 +457,8 @@ export async function PUT(request: Request) {
             }
         }
 
-        if (effectiveGenreIds && effectiveGenreIds.length > 0) {
+        // Wenn effectiveGenreIds definiert ist, auch leere Arrays übernehmen (löscht alle Zuordnungen).
+        if (effectiveGenreIds !== undefined) {
             data.genres = {
                 set: effectiveGenreIds.map((gId: number) => ({ id: gId }))
             };