diff --git a/tools/testing/selftests/bpf/prog_tests/btf.c b/tools/testing/selftests/bpf/prog_tests/btf.c
index 127b8caa3dc1ef..24dd6214394e08 100644
--- a/tools/testing/selftests/bpf/prog_tests/btf.c
+++ b/tools/testing/selftests/bpf/prog_tests/btf.c
@@ -3935,6 +3935,19 @@ static struct btf_raw_test raw_tests[] = {
 	.btf_load_err = true,
 	.err_str = "Invalid type_id",
 },
+{
+	.descr = "decl_tag test #16, func proto, return type",
+	.raw_types = {
+		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),				/* [1] */
+		BTF_VAR_ENC(NAME_TBD, 1, 0),						/* [2] */
+		BTF_TYPE_ENC(NAME_TBD, BTF_INFO_ENC(BTF_KIND_DECL_TAG, 0, 0), 2), (-1),	/* [3] */
+		BTF_FUNC_PROTO_ENC(3, 0),						/* [4] */
+		BTF_END_RAW,
+	},
+	BTF_STR_SEC("\0local\0tag1"),
+	.btf_load_err = true,
+	.err_str = "Invalid return type",
+},
 {
 	.descr = "type_tag test #1",
 	.raw_types = {