diff --git a/certificate.go b/certificate.go
index f682acd..205a2e2 100644
--- a/certificate.go
+++ b/certificate.go
@@ -28,12 +28,12 @@ func getCert(tmdData []byte, id int, numContents uint16) ([]byte, error) {
 	}
 }
 
-func getDefaultCert(cancelCtx context.Context, progressReporter ProgressReporter, client *http.Client) ([]byte, error) {
+func getDefaultCert(cancelCtx context.Context, progressReporter ProgressReporter, client *http.Client, buffer []byte) ([]byte, error) {
 	if len(cetkData) >= 0x350+0x300 {
 		return cetkData[0x350 : 0x350+0x300], nil
 	}
 	cetkDir := path.Join(os.TempDir(), "cetk")
-	if err := downloadFile(cancelCtx, progressReporter, client, "http://ccs.cdn.c.shop.nintendowifi.net/ccs/download/000500101000400a/cetk", cetkDir, true); err != nil {
+	if err := downloadFile(cancelCtx, progressReporter, client, "http://ccs.cdn.c.shop.nintendowifi.net/ccs/download/000500101000400a/cetk", cetkDir, true, buffer); err != nil {
 		return nil, err
 	}
 	cetkData, err := os.ReadFile(cetkDir)
@@ -51,7 +51,7 @@ func getDefaultCert(cancelCtx context.Context, progressReporter ProgressReporter
 	return nil, fmt.Errorf("failed to download OSv10 cetk, length: %d", len(cetkData))
 }
 
-func GenerateCert(tmdData []byte, contentCount uint16, progressReporter ProgressReporter, client *http.Client, cancelCtx context.Context) (bytes.Buffer, error) {
+func GenerateCert(tmdData []byte, contentCount uint16, progressReporter ProgressReporter, client *http.Client, cancelCtx context.Context, buffer []byte) (bytes.Buffer, error) {
 	cert := bytes.Buffer{}
 
 	cert0, err := getCert(tmdData, 0, contentCount)
@@ -66,7 +66,7 @@ func GenerateCert(tmdData []byte, contentCount uint16, progressReporter Progress
 	}
 	cert.Write(cert1)
 
-	defaultCert, err := getDefaultCert(cancelCtx, progressReporter, client)
+	defaultCert, err := getDefaultCert(cancelCtx, progressReporter, client, buffer)
 	if err != nil {
 		return bytes.Buffer{}, err
 	}
diff --git a/cmd/WiiUDownloader/mainwindow.go b/cmd/WiiUDownloader/mainwindow.go
index effa2e3..3fc598c 100644
--- a/cmd/WiiUDownloader/mainwindow.go
+++ b/cmd/WiiUDownloader/mainwindow.go
@@ -265,7 +265,7 @@ func (mw *MainWindow) ShowAll() {
 
 		wiiudownloader.GenerateTicket(filepath.Join(parentDir, "title.tik"), titleID, titleKey, titleVersion)
 
-		cert, err := wiiudownloader.GenerateCert(tmdData, contentCount, mw.progressWindow, http.DefaultClient, context.Background())
+		cert, err := wiiudownloader.GenerateCert(tmdData, contentCount, mw.progressWindow, http.DefaultClient, context.Background(), make([]byte, 0))
 		if err != nil {
 			return
 		}
diff --git a/downloader.go b/downloader.go
index ec28ced..6120113 100644
--- a/downloader.go
+++ b/downloader.go
@@ -41,7 +41,7 @@ func calculateDownloadSpeed(downloaded int64, startTime, endTime time.Time) int6
 	return 0
 }
 
-func downloadFile(ctx context.Context, progressReporter ProgressReporter, client *http.Client, downloadURL, dstPath string, doRetries bool) error {
+func downloadFile(ctx context.Context, progressReporter ProgressReporter, client *http.Client, downloadURL, dstPath string, doRetries bool, buffer []byte) error {
 	filePath := filepath.Base(dstPath)
 
 	var speed int64
@@ -73,7 +73,6 @@ func downloadFile(ctx context.Context, progressReporter ProgressReporter, client
 		}
 		defer file.Close()
 
-		buffer := make([]byte, bufferSize)
 		var downloaded int64
 
 		startTime = time.Now()
@@ -128,8 +127,10 @@ func DownloadTitle(cancelCtx context.Context, titleID, outputDirectory string, d
 		return err
 	}
 
+	buffer := make([]byte, bufferSize)
+
 	tmdPath := filepath.Join(outputDir, "title.tmd")
-	if err := downloadFile(cancelCtx, progressReporter, client, fmt.Sprintf("%s/%s", baseURL, "tmd"), tmdPath, true); err != nil {
+	if err := downloadFile(cancelCtx, progressReporter, client, fmt.Sprintf("%s/%s", baseURL, "tmd"), tmdPath, true, buffer); err != nil {
 		if progressReporter.Cancelled() {
 			return nil
 		}
@@ -147,7 +148,7 @@ func DownloadTitle(cancelCtx context.Context, titleID, outputDirectory string, d
 	}
 
 	tikPath := filepath.Join(outputDir, "title.tik")
-	if err := downloadFile(cancelCtx, progressReporter, client, fmt.Sprintf("%s/%s", baseURL, "cetk"), tikPath, false); err != nil {
+	if err := downloadFile(cancelCtx, progressReporter, client, fmt.Sprintf("%s/%s", baseURL, "cetk"), tikPath, false, buffer); err != nil {
 		if progressReporter.Cancelled() {
 			return nil
 		}
@@ -186,7 +187,7 @@ func DownloadTitle(cancelCtx context.Context, titleID, outputDirectory string, d
 
 	progressReporter.SetDownloadSize(int64(titleSize))
 
-	cert, err := GenerateCert(tmdData, contentCount, progressReporter, client, cancelCtx)
+	cert, err := GenerateCert(tmdData, contentCount, progressReporter, client, cancelCtx, buffer)
 	if err != nil {
 		if progressReporter.Cancelled() {
 			return nil
@@ -230,7 +231,7 @@ func DownloadTitle(cancelCtx context.Context, titleID, outputDirectory string, d
 			return err
 		}
 		filePath := filepath.Join(outputDir, fmt.Sprintf("%08X.app", id))
-		if err := downloadFile(cancelCtx, progressReporter, client, fmt.Sprintf("%s/%08X", baseURL, id), filePath, true); err != nil {
+		if err := downloadFile(cancelCtx, progressReporter, client, fmt.Sprintf("%s/%08X", baseURL, id), filePath, true, buffer); err != nil {
 			if progressReporter.Cancelled() {
 				break
 			}
@@ -240,7 +241,7 @@ func DownloadTitle(cancelCtx context.Context, titleID, outputDirectory string, d
 
 		if tmdData[offset+7]&0x2 == 2 {
 			filePath = filepath.Join(outputDir, fmt.Sprintf("%08X.h3", id))
-			if err := downloadFile(cancelCtx, progressReporter, client, fmt.Sprintf("%s/%08X.h3", baseURL, id), filePath, true); err != nil {
+			if err := downloadFile(cancelCtx, progressReporter, client, fmt.Sprintf("%s/%08X.h3", baseURL, id), filePath, true, buffer); err != nil {
 				if progressReporter.Cancelled() {
 					break
 				}