diff --git a/CHANGES.txt b/CHANGES.txt
index 0fd51ec50f..c84e6436ba 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -45,6 +45,7 @@ Merged from 3.0:
  * Catch UnsatisfiedLinkError in WindowsTimer (CASSANDRA-16085)
  * Avoid removing batch when it's not created during view replication (CASSANDRA-16175)
  * Make the addition of regular column to COMPACT tables throw an InvalidRequestException (CASSANDRA-14564)
+ * Race in CompactionExecutorTest (CASSANDRA-17239)
 
 4.0.1
  * Tolerate missing DNS entry when completing a host replacement (CASSANDRA-16873)
diff --git a/test/unit/org/apache/cassandra/db/compaction/CompactionExecutorTest.java b/test/unit/org/apache/cassandra/db/compaction/CompactionExecutorTest.java
index ab3d9e5c1e..cca29975dc 100644
--- a/test/unit/org/apache/cassandra/db/compaction/CompactionExecutorTest.java
+++ b/test/unit/org/apache/cassandra/db/compaction/CompactionExecutorTest.java
@@ -18,7 +18,6 @@
 
 package org.apache.cassandra.db.compaction;
 
-import java.util.concurrent.Future;
 import java.util.concurrent.TimeUnit;
 
 import org.junit.After;
@@ -27,6 +26,7 @@ import org.junit.Before;
 import org.junit.Test;
 import org.apache.cassandra.concurrent.DebuggableThreadPoolExecutor;
 import org.apache.cassandra.config.DatabaseDescriptor;
+import org.apache.cassandra.utils.concurrent.SimpleCondition;
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
@@ -34,8 +34,12 @@ import static org.junit.Assert.assertNotNull;
 public class CompactionExecutorTest
 {
     static Throwable testTaskThrowable = null;
+    static SimpleCondition afterExecuteCompleted = null;
     private static class TestTaskExecutor extends CompactionManager.CompactionExecutor
     {
+        // afterExecute runs immediately after the task completes, but it may
+        // race with the main thread checking the result, so make the main thread wait
+        // with a simple condition
         @Override
         public void afterExecute(Runnable r, Throwable t)
         {
@@ -44,6 +48,7 @@ public class CompactionExecutorTest
                 t = DebuggableThreadPoolExecutor.extractThrowable(r);
             }
             testTaskThrowable = t;
+            afterExecuteCompleted.signalAll();
         }
         @Override
         protected void beforeExecute(Thread t, Runnable r)
@@ -57,6 +62,8 @@ public class CompactionExecutorTest
     {
         DatabaseDescriptor.daemonInitialization();
         executor = new TestTaskExecutor();
+        testTaskThrowable = null;
+        afterExecuteCompleted = new SimpleCondition();
     }
 
     @After
@@ -66,16 +73,19 @@ public class CompactionExecutorTest
         Assert.assertTrue(executor.awaitTermination(1, TimeUnit.MINUTES));
     }
 
+    void awaitExecution() throws Exception
+    {
+        assert afterExecuteCompleted.await(10, TimeUnit.SECONDS) : "afterExecute failed to complete";
+    }
+
     @Test
     public void testFailedRunnable() throws Exception
     {
-        testTaskThrowable = null;
-        Future<?> tt = executor.submitIfRunning(
+        executor.submitIfRunning(
             () -> { assert false : "testFailedRunnable"; }
             , "compactionExecutorTest");
 
-        while (!tt.isDone())
-            Thread.sleep(10);
+        awaitExecution();
         assertNotNull(testTaskThrowable);
         assertEquals(testTaskThrowable.getMessage(), "testFailedRunnable");
     }
@@ -83,13 +93,11 @@ public class CompactionExecutorTest
     @Test
     public void testFailedCallable() throws Exception
     {
-        testTaskThrowable = null;
-        Future<?> tt = executor.submitIfRunning(
+        executor.submitIfRunning(
             () -> { assert false : "testFailedCallable"; return 1; }
             , "compactionExecutorTest");
 
-        while (!tt.isDone())
-            Thread.sleep(10);
+        awaitExecution();
         assertNotNull(testTaskThrowable);
         assertEquals(testTaskThrowable.getMessage(), "testFailedCallable");
     }
@@ -97,13 +105,11 @@ public class CompactionExecutorTest
     @Test
     public void testExceptionRunnable() throws Exception
     {
-        testTaskThrowable = null;
-        Future<?> tt = executor.submitIfRunning(
+        executor.submitIfRunning(
         () -> { throw new RuntimeException("testExceptionRunnable"); }
         , "compactionExecutorTest");
 
-        while (!tt.isDone())
-            Thread.sleep(10);
+        awaitExecution();
         assertNotNull(testTaskThrowable);
         assertEquals(testTaskThrowable.getMessage(), "testExceptionRunnable");
     }