diff --git a/blobmsg.c b/blobmsg.c
index e04fa53..8e2d73a 100644
--- a/blobmsg.c
+++ b/blobmsg.c
@@ -21,6 +21,7 @@ static const int blob_type[__BLOBMSG_TYPE_LAST] = {
 	[BLOBMSG_TYPE_INT32] = BLOB_ATTR_INT32,
 	[BLOBMSG_TYPE_INT64] = BLOB_ATTR_INT64,
 	[BLOBMSG_TYPE_STRING] = BLOB_ATTR_STRING,
+	[BLOBMSG_TYPE_UNSPEC] = BLOB_ATTR_BINARY,
 };
 
 static uint16_t
@@ -52,7 +53,7 @@ bool blobmsg_check_attr(const struct blob_attr *attr, bool name)
 	len = blobmsg_data_len(attr);
 	data = blobmsg_data(attr);
 
-	if (!id || id > BLOBMSG_TYPE_LAST)
+	if (id > BLOBMSG_TYPE_LAST)
 		return false;
 
 	if (!blob_type[id])
diff --git a/blobmsg_json.c b/blobmsg_json.c
index f629d76..d4f6846 100644
--- a/blobmsg_json.c
+++ b/blobmsg_json.c
@@ -228,6 +228,9 @@ static void blobmsg_format_element(struct strbuf *s, struct blob_attr *attr, boo
 
 	data_str = buf;
 	switch(blob_id(attr)) {
+	case BLOBMSG_TYPE_UNSPEC:
+		sprintf(buf, "null");
+		break;
 	case BLOBMSG_TYPE_BOOL:
 		sprintf(buf, "%s", *(uint8_t *)data ? "true" : "false");
 		break;