1 files changed, 2 insertions, 0 deletions
diff --git a/vm_core.h b/vm_core.h
index c2c1420df..a104778b4 100644
--- a/vm_core.h
+++ b/vm_core.h
@@ -431,9 +431,11 @@ struct rb_thread_struct
     /* for GC */
     VALUE *machine_stack_start;
     VALUE *machine_stack_end;
+    size_t machine_stack_maxsize;
 #ifdef __ia64
     VALUE *machine_register_stack_start;
     VALUE *machine_register_stack_end;
+    size_t machine_register_stack_maxsize;
 #endif
     jmp_buf machine_regs;
     int mark_stack_len;