diff --git a/object-name.c b/object-name.c
index 1e0118e8a6..4407f67ff8 100644
--- a/object-name.c
+++ b/object-name.c
@@ -703,7 +703,7 @@ static int extend_abbrev_len(const struct object_id *oid,
 	while (mad->hex[i] && mad->hex[i] == get_hex_char_from_oid(oid, i))
 		i++;
 
-	if (i < GIT_MAX_RAWSZ && i >= mad->cur_len)
+	if (mad->hex[i] && i >= mad->cur_len)
 		mad->cur_len = i + 1;
 
 	return 0;