diff --git a/src/flb_output.c b/src/flb_output.c
index 675cffbc695..c374cea1352 100644
--- a/src/flb_output.c
+++ b/src/flb_output.c
@@ -720,6 +720,8 @@ struct flb_output_instance *flb_output_new(struct flb_config *config,
     mk_list_init(&instance->upstreams);
     mk_list_init(&instance->flush_list);
     mk_list_init(&instance->flush_list_destroy);
+    mk_list_init(&instance->timer_coro_list);
+    mk_list_init(&instance->timer_coro_list_destroy);
 
     mk_list_add(&instance->_head, &config->outputs);