diff --git a/src/gc.c b/src/gc.c
index d6c881a8f..799e46684 100644
--- a/src/gc.c
+++ b/src/gc.c
@@ -997,6 +997,7 @@ final_marking_phase(mrb_state *mrb, mrb_gc *gc)
 {
   mrb_gc_mark_gv(mrb);
   mark_context(mrb, mrb->c);
+  mark_context(mrb, mrb->root_c);
   mrb_gc_mark(mrb, (struct RBasic*)mrb->exc);
   gc_mark_gray_list(mrb, gc);
   mrb_assert(gc->gray_list == NULL);