diff --git a/lucene/src/java/org/apache/lucene/index/SegmentCoreReaders.java b/lucene/src/java/org/apache/lucene/index/SegmentCoreReaders.java
index 457707ac7bb..35f8f94fe32 100644
--- a/lucene/src/java/org/apache/lucene/index/SegmentCoreReaders.java
+++ b/lucene/src/java/org/apache/lucene/index/SegmentCoreReaders.java
@@ -199,4 +199,9 @@ final class SegmentCoreReaders {
       }
     }
   }
+
+  @Override
+  public String toString() {
+    return "SegmentCoreReader(owner=" + owner + ")";
+  }
 }