gistfile1.txt

diff --git a/core/msg.c b/core/msg.c
index a46875f16e..dbb6b6b6bf 100644
--- a/core/msg.c
+++ b/core/msg.c
@@ -366,7 +366,7 @@ static int _msg_receive(msg_t *m, int block)
         if (sender_prio < THREAD_PRIORITY_IDLE) {
             sched_switch(sender_prio);
         }
-        return 1;
+        return 2;
     }
 
     DEBUG("This should have never been reached!\n");
diff --git a/sys/net/gnrc/network_layer/ipv6/gnrc_ipv6.c b/sys/net/gnrc/network_layer/ipv6/gnrc_ipv6.c
index feb2e8f10f..a62887c250 100644
--- a/sys/net/gnrc/network_layer/ipv6/gnrc_ipv6.c
+++ b/sys/net/gnrc/network_layer/ipv6/gnrc_ipv6.c
@@ -180,7 +180,8 @@ static void *_event_loop(void *args)
     /* start event loop */
     while (1) {
         DEBUG("ipv6: waiting for incoming message.\n");
-        msg_receive(&msg);
+        memset(&msg, 0, sizeof(msg));
+        int res = msg_receive(&msg);
 
         switch (msg.type) {
             case GNRC_NETAPI_MSG_TYPE_RCV:
@@ -220,6 +221,7 @@ static void *_event_loop(void *args)
                 gnrc_ipv6_nib_handle_timer_event(msg.content.ptr, msg.type);
                 break;
             default:
+                printf("ipv6: unknown message type 0x%04x, res=%i\n", msg.type, res);
                 break;
         }
     }