diff --git a/subsys/bluetooth/mesh/transport.c b/subsys/bluetooth/mesh/transport.c
index 1a7b7202b42..bf4fb6b682b 100644
--- a/subsys/bluetooth/mesh/transport.c
+++ b/subsys/bluetooth/mesh/transport.c
@@ -85,11 +85,13 @@ static struct seg_tx {
 				 ctl:1,
 				 aszmic:1,
 				 friend_cred:1;
-	u8_t                     seg_o:5,
+	u8_t                     seg_o:6,       /* Segment being sent. 6 bits to
+						 * prevent overflow in loop.
+						 */
 				 started:1,     /* Start cb called */
-				 sending:1,     /* Sending is in progress */
+				 sending:1;     /* Sending is in progress */
+	u8_t                     nack_count:5,  /* Number of unacked segs */
 				 blocked:1;     /* Blocked by ongoing tx */
-	u8_t                     nack_count;    /* Number of unacked segs */
 	u8_t                     ttl;
 	u8_t                     seg_pending:5, /* Number of segments pending */
 				 attempts:3;