diff --git a/src/test/java/org/fluentd/logger/TestFluentLogger.java b/src/test/java/org/fluentd/logger/TestFluentLogger.java
index b0c2d01..fb65719 100644
--- a/src/test/java/org/fluentd/logger/TestFluentLogger.java
+++ b/src/test/java/org/fluentd/logger/TestFluentLogger.java
@@ -27,6 +27,7 @@
 import static org.junit.Assert.*;
 
 public class TestFluentLogger {
+    private static volatile boolean hasExecuted = false;
     private Logger _logger = LoggerFactory.getLogger(TestFluentLogger.class);
 
     class FixedThreadManager {
@@ -439,9 +440,13 @@ public void run() {
                             logger.flush();
                     }
                     logger.flush();
+                    hasExecuted = true;
                 }
             });
         }
+        while (!hasExecuted) { 
+            Thread.yield(); 
+        }
         Thread.sleep(1000);
         executorService.shutdown();
         executorService.awaitTermination(300, TimeUnit.SECONDS);