diff --git a/examples/6tisch/sixtop/node-sixtop.c b/examples/6tisch/sixtop/node-sixtop.c
index 84598d331..4c60db3a7 100755
--- a/examples/6tisch/sixtop/node-sixtop.c
+++ b/examples/6tisch/sixtop/node-sixtop.c
@@ -63,7 +63,7 @@ AUTOSTART_PROCESSES(&node_process);
 /*---------------------------------------------------------------------------*/
 PROCESS_THREAD(node_process, ev, data)
 {
-  int is_coordinator;
+  static int is_coordinator;
   static int added_num_of_links = 0;
   static struct etimer et;
   struct tsch_neighbor *n;