diff --git a/jetty-io/src/main/java/org/eclipse/jetty/io/ManagedSelector.java b/jetty-io/src/main/java/org/eclipse/jetty/io/ManagedSelector.java
index 1f512c3ae21..2023ff9c328 100644
--- a/jetty-io/src/main/java/org/eclipse/jetty/io/ManagedSelector.java
+++ b/jetty-io/src/main/java/org/eclipse/jetty/io/ManagedSelector.java
@@ -102,7 +102,9 @@ public class ManagedSelector extends ContainerLifeCycle implements Dumpable
         _selectorManager.execute(_strategy::produce);
 
         // Set started only if we really are started
-        submit(s->_started.set(true));
+        Start start = new Start();
+        submit(start);
+        start._started.await();
     }
 
     public int size()
@@ -540,6 +542,18 @@ public class ManagedSelector extends ContainerLifeCycle implements Dumpable
         public void update(Selector selector);
     }
 
+    private class Start implements SelectorUpdate
+    {
+        private final CountDownLatch _started = new CountDownLatch(1);
+
+        @Override
+        public void update(Selector selector)
+        {
+            ManagedSelector.this._started.set(true);
+            _started.countDown();
+        }
+    }
+
     private static class DumpKeys implements SelectorUpdate
     {
         private CountDownLatch latch = new CountDownLatch(1);