diff --git a/core/net/rpl/rpl-dag.c b/core/net/rpl/rpl-dag.c
index baad9946b..6ee195c1c 100644
--- a/core/net/rpl/rpl-dag.c
+++ b/core/net/rpl/rpl-dag.c
@@ -630,7 +630,7 @@ rpl_select_dag(rpl_instance_t *instance, rpl_parent_t *p)
   instance->of->update_metric_container(instance);
   /* Update the DAG rank. */
   best_dag->rank = instance->of->calculate_rank(best_dag->preferred_parent, 0);
-  if(best_dag->rank < best_dag->min_rank) {
+  if(last_parent == NULL || best_dag->rank < best_dag->min_rank) {
     best_dag->min_rank = best_dag->rank;
   } else if(!acceptable_rank(best_dag, best_dag->rank)) {
     PRINTF("RPL: New rank unacceptable!\n");
@@ -1143,13 +1143,6 @@ rpl_process_dio(uip_ipaddr_t *from, rpl_dio_t *dio)
     }
   }
 
-  if(dio->rank == INFINITE_RANK) {
-    PRINTF("RPL: Ignoring DIO from node with infinite rank: ");
-    PRINT6ADDR(from);
-    PRINTF("\n");
-    return;
-  }
-
   if(instance == NULL) {
     PRINTF("RPL: New instance detected: Joining...\n");
     rpl_join_instance(from, dio);