diff --git a/backend/filen/filen.go b/backend/filen/filen.go
index 57d992404..72095d39d 100644
--- a/backend/filen/filen.go
+++ b/backend/filen/filen.go
@@ -355,19 +355,19 @@ type chunkWriter struct {
 	chunkSize       int64
 
 	chunksLock      sync.Mutex
-	knownChunks     map[int][]byte // known chunks to be hashed
-	nextChunkToHash int
+	knownChunks     map[int64][]byte // known chunks to be hashed
+	nextChunkToHash int64
 
 	sizeLock sync.Mutex
 	size     int64
 }
 
 func (cw *chunkWriter) WriteChunk(ctx context.Context, chunkNumber int, reader io.ReadSeeker) (bytesWritten int64, err error) {
-	realChunkNumber := int(int64(chunkNumber) * (cw.chunkSize) / sdk.ChunkSize)
+	realChunkNumber := int64(chunkNumber) * (cw.chunkSize) / sdk.ChunkSize
 	chunk := make([]byte, sdk.ChunkSize, sdk.ChunkSize+cw.EncryptionKey.Cipher.Overhead())
 
 	totalWritten := int64(0)
-	for sliceStart := 0; sliceStart < int(cw.chunkSize); sliceStart += sdk.ChunkSize {
+	for sliceStart := int64(0); sliceStart < cw.chunkSize; sliceStart += sdk.ChunkSize {
 		chunk = chunk[:sdk.ChunkSize]
 		chunkRead := 0
 		for {
@@ -496,7 +496,7 @@ func (f *Fs) OpenChunkWriter(ctx context.Context, remote string, src fs.ObjectIn
 		filen:           f.filen,
 		chunkSize:       chunkSize,
 		bucketAndRegion: make(chan client.V3UploadResponse, 1),
-		knownChunks:     make(map[int][]byte),
+		knownChunks:     make(map[int64][]byte),
 		nextChunkToHash: 0,
 		size:            0,
 	}, nil
@@ -1122,8 +1122,8 @@ func (f *Fs) About(ctx context.Context) (*fs.Usage, error) {
 		return nil, err
 	}
 
-	total := int64(userInfo.MaxStorage)
-	used := int64(userInfo.UsedStorage)
+	total := userInfo.MaxStorage
+	used := userInfo.UsedStorage
 	free := total - used
 	return &fs.Usage{
 		Total:   &total,
diff --git a/go.mod b/go.mod
index 27ee6b8b8..17e88ee57 100644
--- a/go.mod
+++ b/go.mod
@@ -11,7 +11,7 @@ require (
 	github.com/Azure/azure-sdk-for-go/sdk/storage/azblob v1.6.3
 	github.com/Azure/azure-sdk-for-go/sdk/storage/azfile v1.5.3
 	github.com/Azure/go-ntlmssp v0.0.2-0.20251110135918-10b7b7e7cd26
-	github.com/FilenCloudDienste/filen-sdk-go v0.0.35
+	github.com/FilenCloudDienste/filen-sdk-go v0.0.37
 	github.com/Files-com/files-sdk-go/v3 v3.2.264
 	github.com/Max-Sum/base32768 v0.0.0-20230304063302-18e6ce5945fd
 	github.com/a1ex3/zstd-seekable-format-go/pkg v0.10.0
diff --git a/go.sum b/go.sum
index 5b41ee1cc..e765a00f9 100644
--- a/go.sum
+++ b/go.sum
@@ -61,8 +61,8 @@ github.com/AzureAD/microsoft-authentication-library-for-go v1.6.0 h1:XRzhVemXdgv
 github.com/AzureAD/microsoft-authentication-library-for-go v1.6.0/go.mod h1:HKpQxkWaGLJ+D/5H8QRpyQXA1eKjxkFlOMwck5+33Jk=
 github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
 github.com/BurntSushi/xgb v0.0.0-20160522181843-27f122750802/go.mod h1:IVnqGOEym/WlBOVXweHU+Q+/VP0lqqI8lqeDx9IjBqo=
-github.com/FilenCloudDienste/filen-sdk-go v0.0.35 h1:geuYpD/1ZXSp1H3kdW7si+KRUIrHHqM1kk8lqoA8Y9M=
-github.com/FilenCloudDienste/filen-sdk-go v0.0.35/go.mod h1:0cBhKXQg49XbKZZfk5TCDa3sVLP+xMxZTWL+7KY0XR0=
+github.com/FilenCloudDienste/filen-sdk-go v0.0.37 h1:W8S9TrAyZ4//3PXsU6+Bi+fe/6uIL986GyS7PVzIDL4=
+github.com/FilenCloudDienste/filen-sdk-go v0.0.37/go.mod h1:0cBhKXQg49XbKZZfk5TCDa3sVLP+xMxZTWL+7KY0XR0=
 github.com/Files-com/files-sdk-go/v3 v3.2.264 h1:lMHTplAYI9FtmCo/QOcpRxmPA5REVAct1r2riQmDQKw=
 github.com/Files-com/files-sdk-go/v3 v3.2.264/go.mod h1:wGqkOzRu/ClJibvDgcfuJNAqI2nLhe8g91tPlDKRCdE=
 github.com/IBM/go-sdk-core/v5 v5.18.5 h1:g0JRl3sYXJczB/yuDlrN6x22LJ6jIxhp0Sa4ARNW60c=