diff --git a/libntfs-3g/volume.c b/libntfs-3g/volume.c
index f2b47606..06f4647e 100644
--- a/libntfs-3g/volume.c
+++ b/libntfs-3g/volume.c
@@ -378,6 +378,7 @@ mft_has_no_attr_list:
 	/* Update the size fields in the inode. */
 	vol->mft_ni->data_size = vol->mft_na->data_size;
 	vol->mft_ni->allocated_size = vol->mft_na->allocated_size;
+	set_nino_flag(vol->mft_ni, KnownSize);
 
 	/*
 	 * The volume is now setup so we can use all read access functions.