diff --git a/src/btf.c b/src/btf.c
index f18d7e6..8d0d0b6 100644
--- a/src/btf.c
+++ b/src/btf.c
@@ -996,7 +996,7 @@ static struct btf *btf_new_empty(struct btf *base_btf)
 	if (base_btf) {
 		btf->base_btf = base_btf;
 		btf->start_id = btf__type_cnt(base_btf);
-		btf->start_str_off = base_btf->hdr->str_len;
+		btf->start_str_off = base_btf->hdr->str_len + base_btf->start_str_off;
 		btf->swapped_endian = base_btf->swapped_endian;
 	}