diff --git a/mrbgems/mruby-io/src/io.c b/mrbgems/mruby-io/src/io.c
index 6b506c4aa..8d04ed3af 100644
--- a/mrbgems/mruby-io/src/io.c
+++ b/mrbgems/mruby-io/src/io.c
@@ -102,12 +102,11 @@ io_get_open_fptr(mrb_state *mrb, mrb_value io)
 static void
 io_set_process_status(mrb_state *mrb, pid_t pid, int status)
 {
-  struct RClass *c_process, *c_status;
+  struct RClass *c_status = NULL;
   mrb_value v;
 
-  c_status = NULL;
   if (mrb_class_defined_id(mrb, MRB_SYM(Process))) {
-    c_process = mrb_module_get_id(mrb, MRB_SYM(Process));
+    struct RClass *c_process = mrb_module_get_id(mrb, MRB_SYM(Process));
     if (mrb_const_defined(mrb, mrb_obj_value(c_process), MRB_SYM(Status))) {
       c_status = mrb_class_get_under_id(mrb, c_process, MRB_SYM(Status));
     }