diff --git a/lib/mrb.c b/lib/mrb.c
index 09704a328a..34f65d335c 100644
--- a/lib/mrb.c
+++ b/lib/mrb.c
@@ -207,6 +207,7 @@ grn_mrb_load(grn_ctx *ctx, const char *path)
     {
       struct RProc *proc;
       proc = mrb_generate_code(mrb, parser);
+      proc->target_class = mrb->object_class;
       result = mrb_toplevel_run(mrb, proc);
     }
     mrb_parser_free(parser);
diff --git a/vendor/mruby-source b/vendor/mruby-source
index 9d3167cabe..e5b61d34f6 160000
--- a/vendor/mruby-source
+++ b/vendor/mruby-source
@@ -1 +1 @@
-Subproject commit 9d3167cabe64b61ce707a00a3a3108b580cf5d11
+Subproject commit e5b61d34f65cabfbe88f3f1709a1f9cff86585de
diff --git a/vendor/mruby/version b/vendor/mruby/version
index 998307806c..232c2993a6 100644
--- a/vendor/mruby/version
+++ b/vendor/mruby/version
@@ -1 +1 @@
-1.0.0-3239-g9d3167c
+1.0.0-3861-ge5b61d34