diff --git a/src/gc.c b/src/gc.c
index da2fe3800..134b818ee 100644
--- a/src/gc.c
+++ b/src/gc.c
@@ -579,6 +579,8 @@ mark_context(mrb_state *mrb, struct mrb_context *c)
   int i;
   mrb_callinfo *ci;
 
+  if (c->status == MRB_FIBER_TERMINATED) return;
+
   /* mark VM stack */
   mark_context_stack(mrb, c);