diff --git a/src/kernel/mod.rs b/src/kernel/mod.rs
index 135f0a3..bbd9f52 100644
--- a/src/kernel/mod.rs
+++ b/src/kernel/mod.rs
@@ -1,4 +1,5 @@
 mod process;
 pub mod thread;
 pub mod scheduler;
-pub mod mgerror;
\ No newline at end of file
+pub mod mgerror;
+pub mod system;
\ No newline at end of file
diff --git a/src/kernel/scheduler.rs b/src/kernel/scheduler.rs
index 0e71684..3500f65 100644
--- a/src/kernel/scheduler.rs
+++ b/src/kernel/scheduler.rs
@@ -2,8 +2,8 @@ use std::sync::Arc;
 
 use crate::utility::list::List;
 use crate::kernel::thread::Thread;
-use crate::utility::system::{G_CURRENT_THREAD, G_THREAD_TO_BE_DESTROYED};
 
+use super::system::{G_CURRENT_THREAD, G_THREAD_TO_BE_DESTROYED};
 
 pub struct Scheduler {
     ready_list: List<Arc<Thread>>
diff --git a/src/utility/system.rs b/src/kernel/system.rs
similarity index 88%
rename from src/utility/system.rs
rename to src/kernel/system.rs
index 08dc9bf..5f04b2c 100644
--- a/src/utility/system.rs
+++ b/src/kernel/system.rs
@@ -2,9 +2,8 @@ use std::{sync::{RwLock, Arc}};
 
 use lazy_static::lazy_static;
 
-use crate::kernel::{thread::Thread, scheduler::Scheduler};
+use crate::{kernel::{thread::Thread, scheduler::Scheduler}, utility::list::List};
 
-use super::list::List;
 extern crate lazy_static;
 
 lazy_static! {
diff --git a/src/kernel/thread.rs b/src/kernel/thread.rs
index 7f109df..12d9db4 100644
--- a/src/kernel/thread.rs
+++ b/src/kernel/thread.rs
@@ -1,7 +1,7 @@
 use std::sync::Arc;
 
-use super::{process::Process, mgerror::ErrorCode};
-use crate::{simulator::machine::{NUM_INT_REGS, NUM_FP_REGS, STACK_REG}, utility::system::{ObjectType, G_ALIVE, G_SCHEDULER}, kernel::scheduler};
+use super::{process::Process, mgerror::ErrorCode, system::{ObjectType, G_ALIVE, G_SCHEDULER}};
+use crate::{simulator::machine::{NUM_INT_REGS, NUM_FP_REGS, STACK_REG}};
 
 const SIMULATORSTACKSIZE: usize = 32 * 1024;
 
diff --git a/src/utility/mod.rs b/src/utility/mod.rs
index 4b92101..651aed7 100644
--- a/src/utility/mod.rs
+++ b/src/utility/mod.rs
@@ -1,2 +1 @@
-pub mod list;
-pub mod system;
\ No newline at end of file
+pub mod list;
\ No newline at end of file