file.go | 2 ++

diff --git a/file.go b/file.go
index 52b5bfeb41bd62a5e666945bb96b925618ed4e5c..b8550cc7eee9acc355361ee6b1a88763ac466729 100644
--- a/file.go
+++ b/file.go
@@ -71,6 +71,8 @@ 	}
 	return
 }
 
+// Marks pieces in the region of the file for download. This is a helper
+// wrapping Torrent.SetRegionPriority.
 func (f *File) PrioritizeRegion(off, len int64) {
 	if off < 0 || off >= f.length {
 		return