diff --git a/src/main/download/download-manager.ts b/src/main/download/download-manager.ts
index 8610b31..61883f6 100644
--- a/src/main/download/download-manager.ts
+++ b/src/main/download/download-manager.ts
@@ -523,23 +523,37 @@ export class DownloadManager extends EventEmitter {
     pkg.cancelled = true;
     pkg.status = "cancelled";
     pkg.updatedAt = nowMs();
-    for (const itemId of pkg.itemIds) {
+    const outputDir = pkg.outputDir;
+    const itemIds = [...pkg.itemIds];
+
+    for (const itemId of itemIds) {
       const item = this.session.items[itemId];
       if (!item) continue;
       const slot = this.activeTasks.get(itemId);
       if (slot) { slot.abortReason = "cancel"; slot.abortController.abort("cancel"); }
-      if (!isFinishedStatus(item.status)) {
-        item.status = "cancelled";
-        item.fullStatus = "Abgebrochen";
-        item.speedBps = 0;
-        item.updatedAt = nowMs();
+      if (item.status !== "completed") {
+        this.runOutcomes.set(itemId, "cancelled");
       }
       this.releaseTargetPath(itemId);
       this.retryManager.removeItem(itemId);
+      this.cachedDirectUrls.delete(itemId);
+      this.itemContributedBytes.delete(itemId);
+      delete this.session.items[itemId];
+      this.itemCount = Math.max(0, this.itemCount - 1);
     }
+
     this.postProcessor.abortPackage(packageId);
+    this.historyRecordedPackages.delete(packageId);
+    this.hybridExtractRequeue.delete(packageId);
+    this.packagePostProcessTasks.delete(packageId);
+    delete this.session.packages[packageId];
+    this.session.packageOrder = this.session.packageOrder.filter(id => id !== packageId);
+
     this.persistSoon();
     this.emitState();
+
+    // Cleanup artifacts in background
+    void cleanupCancelledPackageArtifactsAsync(outputDir).catch(() => {});
   }
 
   public resetPackage(packageId: string): void {