diff --git a/core/net/rpl/rpl-timers.c b/core/net/rpl/rpl-timers.c
index b4c25df19..d2ff5c97f 100644
--- a/core/net/rpl/rpl-timers.c
+++ b/core/net/rpl/rpl-timers.c
@@ -70,7 +70,7 @@ handle_periodic_timer(void *ptr)
   rpl_recalculate_ranks();
 
   /* handle DIS */
-#ifdef RPL_DIS_SEND
+#if RPL_DIS_SEND
   next_dis++;
   if(rpl_get_any_dag() == NULL && next_dis >= RPL_DIS_INTERVAL) {
     next_dis = 0;