diff --git a/rbd/rbd.go b/rbd/rbd.go
index 48c93b7..b072327 100644
--- a/rbd/rbd.go
+++ b/rbd/rbd.go
@@ -781,6 +781,7 @@ func (image *Image) Write(data []byte) (n int, err error) {
 	return ret, err
 }
 
+// Seek updates the internal file position for the current image.
 func (image *Image) Seek(offset int64, whence int) (int64, error) {
 	switch whence {
 	case SeekSet: