diff --git a/lib/jose/jws/jws.c b/lib/jose/jws/jws.c
index 2b37fd4f9..b568104d3 100644
--- a/lib/jose/jws/jws.c
+++ b/lib/jose/jws/jws.c
@@ -459,7 +459,7 @@ lws_jws_sig_confirm(struct lws_jws_map *map_b64, struct lws_jws_map *map,
 		b = 2;
 
 	if (lws_jws_parse_jose(&jose, map->buf[LJWS_JOSE], map->len[LJWS_JOSE],
-			       temp, &temp_len) < 0) {
+			       temp, &temp_len) < 0 || !jose.alg) {
 		lwsl_notice("%s: parse failed\n", __func__);
 		return -1;
 	}
diff --git a/minimal-examples/api-tests/api-test-jose/jws.c b/minimal-examples/api-tests/api-test-jose/jws.c
index 2236d928a..8fc6ad5ed 100644
--- a/minimal-examples/api-tests/api-test-jose/jws.c
+++ b/minimal-examples/api-tests/api-test-jose/jws.c
@@ -63,7 +63,7 @@ test_jws_none(struct lws_context *context)
 	if (lws_jws_parse_jose(&jose, map.buf[LJWS_JOSE],
 			       map.len[LJWS_JOSE],
 			       (char *)lws_concat_temp(temp, temp_len),
-			       &temp_len) < 0) {
+			       &temp_len) < 0 || !jose.alg) {
 		lwsl_err("%s: JOSE parse failed\n", __func__);
 		goto bail;
 	}
@@ -131,7 +131,8 @@ test_jws_HS256(struct lws_context *context)
 
 	/* parse the JOSE header */
 
-	if (lws_jws_parse_jose(&jose, test1, strlen(test1), temp, &temp_len) < 0) {
+	if (lws_jws_parse_jose(&jose, test1, strlen(test1), temp, &temp_len) < 0 ||
+			!jose.alg) {
 		lwsl_err("%s: JOSE parse failed\n", __func__);
 		goto bail;
 	}