diff --git a/subsys/bluetooth/mesh/net.c b/subsys/bluetooth/mesh/net.c
index 402fbf104d52..5ad410e661fb 100644
--- a/subsys/bluetooth/mesh/net.c
+++ b/subsys/bluetooth/mesh/net.c
@@ -456,10 +456,6 @@ int bt_mesh_net_send(struct bt_mesh_net_tx *tx, struct net_buf *buf,
 	BT_DBG("Payload len %u: %s", buf->len, bt_hex(buf->data, buf->len));
 	BT_DBG("Seq 0x%06x", bt_mesh.seq);
 
-	if (tx->ctx->send_ttl == BT_MESH_TTL_DEFAULT) {
-		tx->ctx->send_ttl = bt_mesh_default_ttl_get();
-	}
-
 	cred = net_tx_cred_get(tx);
 	err = net_header_encode(tx, cred->nid, &buf->b);
 	if (err) {
diff --git a/subsys/bluetooth/mesh/transport.c b/subsys/bluetooth/mesh/transport.c
index 6cd8a54ced22..306a99948c5c 100644
--- a/subsys/bluetooth/mesh/transport.c
+++ b/subsys/bluetooth/mesh/transport.c
@@ -498,12 +498,7 @@ static int send_seg(struct bt_mesh_net_tx *net_tx, struct net_buf_simple *sdu,
 	tx->blocked = blocked;
 	tx->started = 0;
 	tx->ctl = !!ctl_op;
-
-	if (net_tx->ctx->send_ttl == BT_MESH_TTL_DEFAULT) {
-		tx->ttl = bt_mesh_default_ttl_get();
-	} else {
-		tx->ttl = net_tx->ctx->send_ttl;
-	}
+	tx->ttl = net_tx->ctx->send_ttl;
 
 	BT_DBG("SeqZero 0x%04x (segs: %u)",
 	       (uint16_t)(tx->seq_auth & TRANS_SEQ_ZERO_MASK), tx->nack_count);
@@ -638,6 +633,13 @@ int bt_mesh_trans_send(struct bt_mesh_net_tx *tx, struct net_buf_simple *msg,
 		return -EINVAL;
 	}
 
+	if (tx->ctx->send_ttl == BT_MESH_TTL_DEFAULT) {
+		tx->ctx->send_ttl = bt_mesh_default_ttl_get();
+	} else if (tx->ctx->send_ttl > BT_MESH_TTL_MAX) {
+		BT_ERR("TTL too large (max 127)");
+		return -EINVAL;
+	}
+
 	if (msg->len > BT_MESH_SDU_UNSEG_MAX) {
 		tx->ctx->send_rel = true;
 	}
@@ -1024,6 +1026,13 @@ int bt_mesh_ctl_send(struct bt_mesh_net_tx *tx, uint8_t ctl_op, void *data,
 {
 	struct net_buf_simple buf;
 
+	if (tx->ctx->send_ttl == BT_MESH_TTL_DEFAULT) {
+		tx->ctx->send_ttl = bt_mesh_default_ttl_get();
+	} else if (tx->ctx->send_ttl > BT_MESH_TTL_MAX) {
+		BT_ERR("TTL too large (max 127)");
+		return -EINVAL;
+	}
+
 	net_buf_simple_init_with_data(&buf, data, data_len);
 
 	if (data_len > BT_MESH_SDU_UNSEG_MAX) {