diff --git a/eval.c b/eval.c
index c94fbe4275..f5896f6fba 100644
--- a/eval.c
+++ b/eval.c
@@ -1930,7 +1930,7 @@ Init_eval(void)
     rb_define_global_function("untrace_var", rb_f_untrace_var, -1);	/* in variable.c */
 
     rb_vm_register_special_exception(ruby_error_reenter, rb_eFatal, "exception reentered");
-    rb_vm_register_special_exception(ruby_error_sysstack_gc, rb_eFatal, "machine stack overflow while GC is running.");
+    rb_vm_register_special_exception(ruby_error_stackfatal, rb_eFatal, "machine stack overflow in critical region");
 
     id_signo = rb_intern_const("signo");
     id_status = rb_intern_const("status");
diff --git a/vm_core.h b/vm_core.h
index 861cae0018..0105488f60 100644
--- a/vm_core.h
+++ b/vm_core.h
@@ -455,7 +455,7 @@ enum ruby_special_exceptions {
     ruby_error_reenter,
     ruby_error_nomemory,
     ruby_error_sysstack,
-    ruby_error_sysstack_gc,
+    ruby_error_stackfatal,
     ruby_error_stream_closed,
     ruby_special_error_count
 };
diff --git a/vm_insnhelper.c b/vm_insnhelper.c
index 69925c07ea..9e85f38be9 100644
--- a/vm_insnhelper.c
+++ b/vm_insnhelper.c
@@ -58,7 +58,7 @@ rb_threadptr_stack_overflow(rb_thread_t *th)
 {
     if (rb_during_gc()) {
 	th->ec.raised_flag = RAISED_STACKOVERFLOW;
-	th->ec.errinfo = th->vm->special_exceptions[ruby_error_sysstack_gc];
+	th->ec.errinfo = th->vm->special_exceptions[ruby_error_stackfatal];
 	TH_JUMP_TAG(th, TAG_RAISE);
     }
 #ifdef USE_SIGALTSTACK