diff --git a/rsc/src/main/java/org/apache/livy/rsc/driver/RSCDriver.java b/rsc/src/main/java/org/apache/livy/rsc/driver/RSCDriver.java
index f727570..eeba300 100644
--- a/rsc/src/main/java/org/apache/livy/rsc/driver/RSCDriver.java
+++ b/rsc/src/main/java/org/apache/livy/rsc/driver/RSCDriver.java
@@ -37,6 +37,7 @@
 import java.util.concurrent.Executors;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.TimeoutException;
+import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicReference;
 
 import io.netty.channel.ChannelHandler.Sharable;
@@ -92,6 +93,7 @@
   protected final RSCConf livyConf;
 
   private final AtomicReference<ScheduledFuture<?>> idleTimeout;
+  private final AtomicBoolean inShutdown;
 
   public RSCDriver(SparkConf conf, RSCConf livyConf) throws Exception {
     Set<PosixFilePermission> perms = PosixFilePermissions.fromString("rwx------");
@@ -110,6 +112,7 @@
     this.activeJobs = new ConcurrentHashMap<>();
     this.bypassJobs = new ConcurrentLinkedDeque<>();
     this.idleTimeout = new AtomicReference<>();
+    this.inShutdown = new AtomicBoolean(false);
   }
 
   private synchronized void shutdown() {
@@ -217,7 +220,9 @@
       @Override
       public void onSuccess(Void unused) {
         clients.remove(client);
-        setupIdleTimeout();
+        if (!inShutdown.get()) {
+          setupIdleTimeout();
+        }
       }
     });
     LOG.debug("Registered new connection from {}.", client.getChannel());
@@ -304,6 +309,7 @@
   }
 
   private void shutdownServer() {
+    inShutdown.compareAndSet(false, true);
     if (server != null) {
       server.close();
     }