diff --git a/include/osmocore/msgb.h b/include/osmocore/msgb.h
index 7de242b..4f0c8c3 100644
--- a/include/osmocore/msgb.h
+++ b/include/osmocore/msgb.h
@@ -67,10 +67,16 @@
 extern struct msgb *msgb_dequeue(struct llist_head *queue);
 extern void msgb_reset(struct msgb *m);
 
+#define msgb_l1(m)	((void *)(m->l1h))
 #define msgb_l2(m)	((void *)(m->l2h))
 #define msgb_l3(m)	((void *)(m->l3h))
 #define msgb_sms(m)	((void *)(m->smsh))
 
+static inline unsigned int msgb_l1len(const struct msgb *msgb)
+{
+	return msgb->tail - (uint8_t *)msgb_l1(msgb);
+}
+
 static inline unsigned int msgb_l2len(const struct msgb *msgb)
 {
 	return msgb->tail - (uint8_t *)msgb_l2(msgb);