diff --git a/src/vm.c b/src/vm.c
index 826cdafef..c78799c6d 100644
--- a/src/vm.c
+++ b/src/vm.c
@@ -788,6 +788,10 @@ mrb_run(mrb_state *mrb, struct RProc *proc, mrb_value self)
         /* setup environment for calling method */
         proc = m;
         irep = m->body.irep;
+	if (!irep) {
+	  mrb->stack[0] = mrb_nil_value();
+	  goto L_RETURN;
+	}
         pool = irep->pool;
         syms = irep->syms;
         ci->nregs = irep->nregs;