diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c
index 8d0d0b645a75e..b1977888b35ed 100644
--- a/tools/lib/bpf/btf.c
+++ b/tools/lib/bpf/btf.c
@@ -995,6 +995,7 @@ static struct btf *btf_new_empty(struct btf *base_btf)
 
 	if (base_btf) {
 		btf->base_btf = base_btf;
+		btf->ptr_sz = base_btf->ptr_sz;
 		btf->start_id = btf__type_cnt(base_btf);
 		btf->start_str_off = base_btf->hdr->str_len + base_btf->start_str_off;
 		btf->swapped_endian = base_btf->swapped_endian;