diff --git a/examples/er-rest-example/project-conf.h b/examples/er-rest-example/project-conf.h
index 3d894a5d4..adcb75ee1 100644
--- a/examples/er-rest-example/project-conf.h
+++ b/examples/er-rest-example/project-conf.h
@@ -100,6 +100,9 @@
 #undef RPL_CONF_WITH_DAO_ACK
 #define RPL_CONF_WITH_DAO_ACK          0
 
+#undef RPL_CONF_OF
+#define RPL_CONF_OF                    rpl_of0
+
 /* Enable client-side support for COAP observe */
 #define COAP_OBSERVE_CLIENT 1
 #endif /* __PROJECT_ERBIUM_CONF_H__ */