diff --git a/client-mr/core/src/test/java/org/apache/hadoop/mapreduce/task/reduce/FetcherTest.java b/client-mr/core/src/test/java/org/apache/hadoop/mapreduce/task/reduce/FetcherTest.java
index 7fd6873095..6beaaa6cf3 100644
--- a/client-mr/core/src/test/java/org/apache/hadoop/mapreduce/task/reduce/FetcherTest.java
+++ b/client-mr/core/src/test/java/org/apache/hadoop/mapreduce/task/reduce/FetcherTest.java
@@ -192,6 +192,7 @@ public void writeAndReadDataMergeFailsTestWithRss() throws Throwable {
     assertEquals(2, ((MockMergeManagerImpl)merger).happenedFails.size());
   }
 
+  @Test
   public void testCodecIsDuplicated() throws Exception {
     fs = FileSystem.getLocal(conf);
     BZip2Codec codec = new BZip2Codec();