diff --git a/net/ip/contiki/ipv6/uip-ds6.c b/net/ip/contiki/ipv6/uip-ds6.c
index 417c47ebaf3..a0f60aec34c 100644
--- a/net/ip/contiki/ipv6/uip-ds6.c
+++ b/net/ip/contiki/ipv6/uip-ds6.c
@@ -268,7 +268,7 @@ uip_ds6_prefix_add(uip_ipaddr_t *ipaddr, uint8_t ipaddrlen,
     locprefix->plifetime = ptime;
     PRINTF("Adding prefix ");
     PRINT6ADDR(&locprefix->ipaddr);
-    PRINTF("length %u, flags %x, Valid lifetime %lx, Preffered lifetime %lx\n",
+    PRINTF(" length %u, flags %x, Valid lifetime %lx, Preffered lifetime %lx\n",
        ipaddrlen, flags, vtime, ptime);
     return locprefix;
   } else {
@@ -298,7 +298,7 @@ uip_ds6_prefix_add(uip_ipaddr_t *ipaddr, uint8_t ipaddrlen,
     }
     PRINTF("Adding prefix ");
     PRINT6ADDR(&locprefix->ipaddr);
-    PRINTF("length %u, vlifetime%lu\n", ipaddrlen, interval);
+    PRINTF(" length %u, vlifetime %lu\n", ipaddrlen, interval);
   }
   return NULL;
 }