the file index header checksum applies to on-disk data
diff --git a/lib/got_file_index_priv.h b/lib/got_file_index_priv.h
index eef7ed2..c1fb905 100644
--- a/lib/got_file_index_priv.h
+++ b/lib/got_file_index_priv.h
@@ -65,5 +65,5 @@ struct got_file_index_hdr {
uint32_t version; /* big-endian on disk */
uint32_t nentries; /* big-endian on disk */
struct got_file_index_entry *entries; /* big-endian on disk */
- uint8_t sha1[SHA1_DIGEST_LENGTH]; /* checksum of above data */
+ uint8_t sha1[SHA1_DIGEST_LENGTH]; /* checksum of above on-disk data */
};