use SystemStackError instead of RuntimeError

2 files changed, 2 insertions, 1 deletions

diff --git a/src/error.c b/src/error.c
index dcb6063f8..d472f7f95 100644
--- a/src/error.c
+++ b/src/error.c
@@ -455,4 +455,5 @@ mrb_init_exception(mrb_state *mrb)
   mrb->nomem_err = mrb_obj_ptr(mrb_exc_new_str(mrb, runtime_error, mrb_str_new_lit(mrb, "Out of memory")));
   script_error = mrb_define_class(mrb, "ScriptError", mrb->eException_class);                /* 15.2.37 */
   mrb_define_class(mrb, "SyntaxError", script_error);                                        /* 15.2.38 */
+  mrb_define_class(mrb, "SystemStackError", exception);
 }
diff --git a/src/vm.c b/src/vm.c
index 20a51eff4..33e8eefb3 100644
--- a/src/vm.c
+++ b/src/vm.c
@@ -160,7 +160,7 @@ stack_extend_alloc(mrb_state *mrb, int room, int keep)
      to prevent infinite recursion. However, do this only after resizing the stack, so mrb_raise has stack space to work with. */
   if (size > MRB_STACK_MAX) {
     init_new_stack_space(mrb, room, keep);
-    mrb_raise(mrb, E_RUNTIME_ERROR, "stack level too deep. (limit=" TO_STR(MRB_STACK_MAX) ")");
+    mrb_raise(mrb, E_SYSSTACK_ERROR, "stack level too deep. (limit=" TO_STR(MRB_STACK_MAX) ")");
   }
 }