check saved_ec.cfp

1 files changed, 3 insertions, 1 deletions

diff --git a/cont.c b/cont.c
index c16c697ee7..ba6120f9cd 100644
--- a/cont.c
+++ b/cont.c
@@ -834,7 +834,9 @@ cont_mark(void *ptr)
     RUBY_MARK_ENTER("cont");
     rb_gc_mark_no_pin(cont->value);
 
-    rb_execution_context_mark(&cont->saved_ec);
+    if (cont->saved_ec.cfp) {
+        rb_execution_context_mark(&cont->saved_ec);
+    }
     rb_gc_mark(cont_thread_value(cont));
 
     if (cont->saved_vm_stack.ptr) {