diff --git a/libguile/root.c b/libguile/root.c
index 6f7d20297..93405f8a2 100644
--- a/libguile/root.c
+++ b/libguile/root.c
@@ -80,6 +80,7 @@ root_mark (SCM root)
   scm_gc_mark (s->cur_errp);
   /* No need to gc mark def_loadp */
   scm_gc_mark (s->fluids);
+  scm_gc_mark (s->active_asyncs);
   return SCM_ROOT_STATE (root) -> parent;
 }