diff --git a/regression-tests/21-large-rpl/code/router/project-conf.h b/regression-tests/21-large-rpl/code/router/project-conf.h
index eb0b0b1a7..bec41cd5e 100644
--- a/regression-tests/21-large-rpl/code/router/project-conf.h
+++ b/regression-tests/21-large-rpl/code/router/project-conf.h
@@ -7,5 +7,5 @@
 #undef NBR_TABLE_CONF_MAX_NEIGHBORS
 #define NBR_TABLE_CONF_MAX_NEIGHBORS             8
 
-/*#define RPL_CONF_DEFAULT_LIFETIME_UNIT           10
-  #define RPL_CONF_DEFAULT_LIFETIME                10*/
+#define RPL_CONF_DEFAULT_LIFETIME_UNIT           60
+#define RPL_CONF_DEFAULT_LIFETIME                5