diff --git a/src/main/java/org/apache/lucene/index/TrackingConcurrentMergeScheduler.java b/src/main/java/org/apache/lucene/index/TrackingConcurrentMergeScheduler.java
index cb2f70caefc..f81a5ced59c 100644
--- a/src/main/java/org/apache/lucene/index/TrackingConcurrentMergeScheduler.java
+++ b/src/main/java/org/apache/lucene/index/TrackingConcurrentMergeScheduler.java
@@ -78,7 +78,7 @@ public class TrackingConcurrentMergeScheduler extends ConcurrentMergeScheduler {
     @Override
     protected void doMerge(MergePolicy.OneMerge merge) throws IOException {
         int totalNumDocs = merge.totalNumDocs();
-        long totalSizeInBytes = merge.totalBytesSize();
+        long totalSizeInBytes = merge.estimatedMergeBytes;
         long time = System.currentTimeMillis();
         currentMerges.inc();
         currentMergesNumDocs.inc(totalNumDocs);
diff --git a/src/main/java/org/apache/lucene/index/TrackingSerialMergeScheduler.java b/src/main/java/org/apache/lucene/index/TrackingSerialMergeScheduler.java
index e763bbf470a..b7523e5e5ea 100644
--- a/src/main/java/org/apache/lucene/index/TrackingSerialMergeScheduler.java
+++ b/src/main/java/org/apache/lucene/index/TrackingSerialMergeScheduler.java
@@ -88,7 +88,7 @@ public class TrackingSerialMergeScheduler extends MergeScheduler {
             writer.mergeInit(merge);
 
             int totalNumDocs = merge.totalNumDocs();
-            long totalSizeInBytes = merge.totalBytesSize();
+            long totalSizeInBytes = merge.estimatedMergeBytes;
             long time = System.currentTimeMillis();
             currentMerges.inc();
             currentMergesNumDocs.inc(totalNumDocs);