diff --git a/src/kernel/exception.rs b/src/kernel/exception.rs
index 0cf5921..de4defe 100644
--- a/src/kernel/exception.rs
+++ b/src/kernel/exception.rs
@@ -65,16 +65,12 @@ fn syscall(machine: &mut Machine, system: &mut System) -> Result<MachineOk, Mach
     match call_type {
         SC_SHUTDOWN => Ok(MachineOk::Shutdown),
         SC_EXIT => {
-            match &system.get_thread_manager().g_current_thread {
-                Some(th) => {
-                    let th = Rc::clone(th);
-                    system.get_thread_manager().thread_finish(machine, th);
-                    Ok(MachineOk::Ok)
-                },
-                None => {
-                    Err("Current thread is None".into())
-                }
-            }
+            let th = match &system.get_thread_manager().g_current_thread {
+                Some(th) => th,
+                None => Err("Current thread is None".into())
+            }?;
+            system.get_thread_manager().thread_finish(machine, th);
+            Ok(MachineOk::Ok)
         },
         SC_EXEC => todo!(),
         SC_JOIN => todo!(),