diff --git a/src/Adaptive.Agrona/Concurrent/AgentRunner.cs b/src/Adaptive.Agrona/Concurrent/AgentRunner.cs
index 73533ad..bc1e812 100644
--- a/src/Adaptive.Agrona/Concurrent/AgentRunner.cs
+++ b/src/Adaptive.Agrona/Concurrent/AgentRunner.cs
@@ -191,7 +191,7 @@ public void Dispose()
                     _errorHandler.OnError(ex);
                 }
             }
-            if (TOMBSTONE != thread)
+            else if (TOMBSTONE != thread)
             {
                 while (true)
                 {