diff --git a/lucene/core/src/test/org/apache/lucene/index/TestIndexWriterMerging.java b/lucene/core/src/test/org/apache/lucene/index/TestIndexWriterMerging.java
index 0b79b9611c6..295c1efbf26 100644
--- a/lucene/core/src/test/org/apache/lucene/index/TestIndexWriterMerging.java
+++ b/lucene/core/src/test/org/apache/lucene/index/TestIndexWriterMerging.java
@@ -353,6 +353,7 @@ public class TestIndexWriterMerging extends LuceneTestCase
     dir.close();
   }
   
+  @Slow
   public void testNoWaitClose() throws Throwable {
     Directory directory = newDirectory();