diff --git a/util/io/src/service.rs b/util/io/src/service.rs
index d7bba5b4d..6086acadd 100644
--- a/util/io/src/service.rs
+++ b/util/io/src/service.rs
@@ -394,7 +394,7 @@ impl<Message> IoChannel<Message> where Message: Send + Clone + Sync + 'static {
 /// 'Message' is a notification message type
 pub struct IoService<Message> where Message: Send + Sync + Clone + 'static {
 	panic_handler: Arc<PanicHandler>,
-	thread: Option<JoinHandle<()>>,
+	thread: Mutex<Option<JoinHandle<()>>>,
 	host_channel: Mutex<Sender<IoMessage<Message>>>,
 	handlers: Arc<RwLock<Slab<Arc<IoHandler<Message>>, HandlerId>>>,
 }
@@ -424,19 +424,19 @@ impl<Message> IoService<Message> where Message: Send + Sync + Clone + 'static {
 		});
 		Ok(IoService {
 			panic_handler: panic_handler,
-			thread: Some(thread),
+			thread: Mutex::new(Some(thread)),
 			host_channel: Mutex::new(channel),
 			handlers: handlers,
 		})
 	}
 
-	pub fn stop(&mut self) {
+	pub fn stop(&self) {
 		trace!(target: "shutdown", "[IoService] Closing...");
 		// Clear handlers so that shared pointers are not stuck on stack
 		// in Channel::send_sync
 		self.handlers.write().clear();
 		self.host_channel.lock().send(IoMessage::Shutdown).unwrap_or_else(|e| warn!("Error on IO service shutdown: {:?}", e));
-		if let Some(thread) = self.thread.take() {
+		if let Some(thread) = self.thread.lock().take() {
 			thread.join().unwrap_or_else(|e| {
 				debug!(target: "shutdown", "Error joining IO service event loop thread: {:?}", e);
 			});