diff --git a/sys/net/gnrc/link_layer/lwmac/lwmac.c b/sys/net/gnrc/link_layer/lwmac/lwmac.c
index d9627a0e79..ef21508d5a 100644
--- a/sys/net/gnrc/link_layer/lwmac/lwmac.c
+++ b/sys/net/gnrc/link_layer/lwmac/lwmac.c
@@ -524,8 +524,6 @@ static void _rx_management(gnrc_netif2_t *netif)
 
 static void _tx_management_stopped(gnrc_netif2_t *netif)
 {
-    gnrc_pktsnip_t *pkt;
-
     /* If there is packet remaining for retransmission,
      * retransmit it (i.e., the retransmission scheme of LWMAC). */
     if (netif->mac.tx.packet != NULL) {
@@ -536,6 +534,8 @@ static void _tx_management_stopped(gnrc_netif2_t *netif)
         gnrc_lwmac_tx_update(netif);
     }
     else {
+        gnrc_pktsnip_t *pkt;
+
         if ((pkt = gnrc_priority_pktqueue_pop(
                  &netif->mac.tx.current_neighbor->queue))) {
             netif->mac.tx.tx_retry_count = 0;
diff --git a/sys/net/gnrc/link_layer/lwmac/tx_state_machine.c b/sys/net/gnrc/link_layer/lwmac/tx_state_machine.c
index c201b50968..ae68acb68d 100644
--- a/sys/net/gnrc/link_layer/lwmac/tx_state_machine.c
+++ b/sys/net/gnrc/link_layer/lwmac/tx_state_machine.c
@@ -378,6 +378,7 @@ static bool _send_data(gnrc_netif2_t *netif)
     gnrc_pktsnip_t *pkt = netif->mac.tx.packet;
     gnrc_pktsnip_t *pkt_payload;
 
+    assert(pkt != NULL);
     /* Enable Auto ACK again */
     netopt_enable_t autoack = NETOPT_ENABLE;
     netif->dev->driver->set(netif->dev, NETOPT_AUTOACK,
@@ -451,9 +452,7 @@ static bool _send_data(gnrc_netif2_t *netif)
     int res = _gnrc_lwmac_transmit(netif, pkt);
     if (res < 0) {
         LOG_ERROR("ERROR: [LWMAC-tx] Send data failed.");
-        if (pkt != NULL) {
-            gnrc_pktbuf_release(pkt);
-        }
+        gnrc_pktbuf_release(pkt);
         /* clear packet point to avoid TX retry */
         netif->mac.tx.packet = NULL;
         return false;