diff --git a/src/vm.c b/src/vm.c
index 09b0c767e..7d63b939e 100644
--- a/src/vm.c
+++ b/src/vm.c
@@ -1497,16 +1497,15 @@ RETRY_TRY_BLOCK:
       ci->target_class = MRB_PROC_TARGET_CLASS(m);
       ci->proc = m;
       if (MRB_PROC_ENV_P(m)) {
-        mrb_sym mid;
         struct REnv *e = MRB_PROC_ENV(m);
 
-        ci->mid = mid = e->mid;
+        ci->mid = e->mid;
         if (!e->stack) {
           e->stack = mrb->c->stack;
         }
       }
 
-      /* prepare stack */
+      /* prepare stack */vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvh[---------------,,,,]cv
       if (MRB_PROC_CFUNC_P(m)) {
         recv = MRB_PROC_CFUNC(m)(mrb, recv);
         mrb_gc_arena_restore(mrb, ai);