diff --git a/core/net/ip/tcpip.c b/core/net/ip/tcpip.c
index 1a1dbf628..3b1091b9d 100644
--- a/core/net/ip/tcpip.c
+++ b/core/net/ip/tcpip.c
@@ -673,9 +673,9 @@ tcpip_ipv6_output(void)
     uip_ds6_set_lladdr_from_iid(&lladdr, nexthop);
     if((nbr = uip_ds6_nbr_add(nexthop, &lladdr,
         0, NBR_REACHABLE, NBR_TABLE_REASON_IPV6_ND_AUTOFILL, NULL)) == NULL) {
-      PRINTF("tcpip_ipv6_output: failed to autofill neighbor cache for host ");
-      PRINT6ADDR(nexthop);
-      PRINTF("\n");
+      LOG_ERR("output: failed to autofill neighbor cache for host ");
+      LOG_ERR_6ADDR(nexthop);
+      LOG_ERR("\n");
       goto exit;
     }
    }
diff --git a/core/net/mac/csma/csma-output.c b/core/net/mac/csma/csma-output.c
index d33b812e6..555c8e88a 100644
--- a/core/net/mac/csma/csma-output.c
+++ b/core/net/mac/csma/csma-output.c
@@ -57,7 +57,7 @@
 
 /* Log configuration */
 #include "sys/log.h"
-#define LOG_MODULE "
+#define LOG_MODULE "CSMA"
 #define LOG_LEVEL MAC_LOG_LEVEL
 
 /* Constants of the IEEE 802.15.4 standard */