diff --git a/curator-client/src/main/java/org/apache/curator/CuratorZookeeperClient.java b/curator-client/src/main/java/org/apache/curator/CuratorZookeeperClient.java
index ecb072f65..1007b5988 100644
--- a/curator-client/src/main/java/org/apache/curator/CuratorZookeeperClient.java
+++ b/curator-client/src/main/java/org/apache/curator/CuratorZookeeperClient.java
@@ -399,6 +399,9 @@ void removeParentWatcher(Watcher watcher) {
     public void internalBlockUntilConnectedOrTimedOut() throws InterruptedException {
         long waitTimeMs = connectionTimeoutMs;
         while (!state.isConnected() && (waitTimeMs > 0)) {
+            if (!started.get()) {
+                throw new IllegalStateException("Client is not started or has been closed");
+            }
             final CountDownLatch latch = new CountDownLatch(1);
             Watcher tempWatcher = new Watcher() {
                 @Override