diff --git a/extlib/benz/include/picrin/irep.h b/extlib/benz/include/picrin/irep.h
index cf612c0e..bba4e2f3 100644
--- a/extlib/benz/include/picrin/irep.h
+++ b/extlib/benz/include/picrin/irep.h
@@ -60,6 +60,11 @@ struct pic_code {
   } u;
 };
 
+#define PIC_INIT_CODE_I(code, op, ival) do {    \
+    code.insn = op;                             \
+    code.u.i = ival;                            \
+  } while (0)
+
 struct pic_irep {
   PIC_OBJECT_HEADER
   pic_sym *name;
diff --git a/extlib/benz/vm.c b/extlib/benz/vm.c
index 682a873c..5b426cd8 100644
--- a/extlib/benz/vm.c
+++ b/extlib/benz/vm.c
@@ -1151,14 +1151,14 @@ pic_apply(pic_state *pic, struct pic_proc *proc, pic_value args)
 pic_value
 pic_apply_trampoline(pic_state *pic, struct pic_proc *proc, pic_value args)
 {
-  static const pic_code iseq[2] = {
-    { OP_NOP, { .i = 0 } },
-    { OP_TAILCALL, { .i = -1 } }
-  };
+  static pic_code iseq[2];
 
   pic_value v, it, *sp;
   pic_callinfo *ci;
 
+  PIC_INIT_CODE_I(iseq[0], OP_NOP, 0);
+  PIC_INIT_CODE_I(iseq[1], OP_TAILCALL, -1);
+
   *pic->sp++ = pic_obj_value(proc);
 
   sp = pic->sp;