diff --git a/mrbgems/mruby-kernel-ext/src/kernel.c b/mrbgems/mruby-kernel-ext/src/kernel.c
index d2f0783be..cbba86359 100644
--- a/mrbgems/mruby-kernel-ext/src/kernel.c
+++ b/mrbgems/mruby-kernel-ext/src/kernel.c
@@ -231,9 +231,7 @@ static mrb_value
 mrb_f_string(mrb_state *mrb, mrb_value self)
 {
   mrb_value arg = mrb_get_arg1(mrb);
-  mrb_value tmp;
-
-  tmp = mrb_type_convert(mrb, arg, MRB_TT_STRING, MRB_SYM(to_s));
+  mrb_value tmp = mrb_type_convert(mrb, arg, MRB_TT_STRING, MRB_SYM(to_s));
   return tmp;
 }
 
@@ -250,9 +248,7 @@ static mrb_value
 mrb_f_array(mrb_state *mrb, mrb_value self)
 {
   mrb_value arg = mrb_get_arg1(mrb);
-  mrb_value tmp;
-
-  tmp = mrb_type_convert_check(mrb, arg, MRB_TT_ARRAY, MRB_SYM(to_a));
+  mrb_value tmp = mrb_type_convert_check(mrb, arg, MRB_TT_ARRAY, MRB_SYM(to_a));
   if (mrb_nil_p(tmp)) {
     return mrb_ary_new_from_values(mrb, 1, &arg);
   }