diff --git a/core/src/test/java/org/elasticsearch/cluster/service/ClusterServiceTests.java b/core/src/test/java/org/elasticsearch/cluster/service/ClusterServiceTests.java
index 026d3a16185..a5d4790f742 100644
--- a/core/src/test/java/org/elasticsearch/cluster/service/ClusterServiceTests.java
+++ b/core/src/test/java/org/elasticsearch/cluster/service/ClusterServiceTests.java
@@ -150,6 +150,7 @@ public class ClusterServiceTests extends ESTestCase {
 
     public void testTimedOutUpdateTaskCleanedUp() throws Exception {
         final CountDownLatch block = new CountDownLatch(1);
+        final CountDownLatch blockCompleted = new CountDownLatch(1);
         clusterService.submitStateUpdateTask("block-task", new ClusterStateUpdateTask() {
             @Override
             public ClusterState execute(ClusterState currentState) {
@@ -158,6 +159,7 @@ public class ClusterServiceTests extends ESTestCase {
                 } catch (InterruptedException e) {
                     throw new RuntimeException(e);
                 }
+                blockCompleted.countDown();
                 return currentState;
             }
 
@@ -187,6 +189,7 @@ public class ClusterServiceTests extends ESTestCase {
         });
         block.countDown();
         block2.await();
+        blockCompleted.await();
         synchronized (clusterService.updateTasksPerExecutor) {
             assertTrue("expected empty map but was " + clusterService.updateTasksPerExecutor,
                 clusterService.updateTasksPerExecutor.isEmpty());