1 files changed, 1 insertions, 1 deletions
diff --git a/eval.c b/eval.c
index d7073c7330..e1b33c2f19 100644
--- a/eval.c
+++ b/eval.c
@@ -7732,7 +7732,7 @@ rb_thread_schedule()
 	    next = th;
 	    break;
 	}
-	if (th->status == THREAD_RUNNABLE) {
+	if (th->status == THREAD_RUNNABLE && th->stk_ptr) {
 	    if (!next || next->priority < th->priority) 
 	       next = th;
 	}