diff --git a/core/net/ip/tcpip.c b/core/net/ip/tcpip.c
index 67c837591..570793c48 100644
--- a/core/net/ip/tcpip.c
+++ b/core/net/ip/tcpip.c
@@ -586,7 +586,16 @@ tcpip_ipv6_output(void)
 	    /* This should be copied from the ext header... */
 	    UIP_IP_BUF->proto = proto;
 	  }
-	  UIP_FALLBACK_INTERFACE.output();
+	  /* Inform the other end that the destination is not reachable. If it's
+	   * not informed routes might get lost unexpectedly until there's a need
+	   * to send a new packet to the peer */
+	  if(UIP_FALLBACK_INTERFACE.output() < 0) {
+	    PRINTF("FALLBACK: output error. Reporting DST UNREACH\n");
+	    uip_icmp6_error_output(ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_ADDR, 0);
+	    uip_flags = 0;
+	    tcpip_ipv6_output();
+	    return;
+	  }
 #else
           PRINTF("tcpip_ipv6_output: Destination off-link but no route\n");
 #endif /* !UIP_FALLBACK_INTERFACE */
diff --git a/core/net/ip/uip.h b/core/net/ip/uip.h
index a85929554..879b74421 100644
--- a/core/net/ip/uip.h
+++ b/core/net/ip/uip.h
@@ -1429,7 +1429,13 @@ extern struct uip_udp_conn uip_udp_conns[UIP_UDP_CONNS];
 
 struct uip_fallback_interface {
   void (*init)(void);
-  void (*output)(void);
+  /**
+   * \retval >=0
+   * 	in case of success
+   * \retval <0
+   *	in case of failure
+   */
+  int (*output)(void);
 };
 
 #if UIP_CONF_ICMP6