diff --git a/lucene/core/src/java/org/apache/lucene/index/IndexWriter.java b/lucene/core/src/java/org/apache/lucene/index/IndexWriter.java
index 0b0b7a599c4..152d5d5a15e 100644
--- a/lucene/core/src/java/org/apache/lucene/index/IndexWriter.java
+++ b/lucene/core/src/java/org/apache/lucene/index/IndexWriter.java
@@ -2295,7 +2295,7 @@ public class IndexWriter implements Closeable, TwoPhaseCommit {
 
       SegmentMerger merger = new SegmentMerger(info, infoStream, trackingDir, config.getTermIndexInterval(),
                                                MergeState.CheckAbort.NONE, payloadProcessorProvider,
-                                               globalFieldNumberMap, codec, context);
+                                               globalFieldNumberMap, context);
 
       for (IndexReader reader : readers) {    // add new indexes
         merger.add(reader);
@@ -3439,7 +3439,7 @@ public class IndexWriter implements Closeable, TwoPhaseCommit {
     final TrackingDirectoryWrapper dirWrapper = new TrackingDirectoryWrapper(directory);
 
     SegmentMerger merger = new SegmentMerger(merge.info.info, infoStream, dirWrapper, config.getTermIndexInterval(), checkAbort,
-                                             payloadProcessorProvider, globalFieldNumberMap, codec, context);
+                                             payloadProcessorProvider, globalFieldNumberMap, context);
 
     if (infoStream.isEnabled("IW")) {
       infoStream.message("IW", "merging " + segString(merge.segments));
diff --git a/lucene/core/src/java/org/apache/lucene/index/SegmentMerger.java b/lucene/core/src/java/org/apache/lucene/index/SegmentMerger.java
index f81072a1502..f85e83ba0d2 100644
--- a/lucene/core/src/java/org/apache/lucene/index/SegmentMerger.java
+++ b/lucene/core/src/java/org/apache/lucene/index/SegmentMerger.java
@@ -59,7 +59,7 @@ final class SegmentMerger {
   // NOT the same!!
   SegmentMerger(SegmentInfo segmentInfo, InfoStream infoStream, Directory dir, int termIndexInterval,
                 MergeState.CheckAbort checkAbort, PayloadProcessorProvider payloadProcessorProvider,
-                FieldInfos.FieldNumbers fieldNumbers, Codec codec, IOContext context) {
+                FieldInfos.FieldNumbers fieldNumbers, IOContext context) {
     mergeState.segmentInfo = segmentInfo;
     mergeState.infoStream = infoStream;
     mergeState.readers = new ArrayList<MergeState.IndexReaderAndLiveDocs>();
@@ -67,7 +67,7 @@ final class SegmentMerger {
     mergeState.payloadProcessorProvider = payloadProcessorProvider;
     directory = dir;
     this.termIndexInterval = termIndexInterval;
-    this.codec = codec;
+    this.codec = segmentInfo.getCodec();
     this.context = context;
     this.fieldInfosBuilder = new FieldInfos.Builder(fieldNumbers);
   }
diff --git a/lucene/core/src/test/org/apache/lucene/index/TestDoc.java b/lucene/core/src/test/org/apache/lucene/index/TestDoc.java
index 0d26b9081e7..96187c878d3 100644
--- a/lucene/core/src/test/org/apache/lucene/index/TestDoc.java
+++ b/lucene/core/src/test/org/apache/lucene/index/TestDoc.java
@@ -200,7 +200,7 @@ public class TestDoc extends LuceneTestCase {
       final SegmentInfo si = new SegmentInfo(si1.info.dir, Constants.LUCENE_MAIN_VERSION, merged, 10000, -1, merged, false, null, false, codec, null, null);
 
       SegmentMerger merger = new SegmentMerger(si, InfoStream.getDefault(), trackingDir, IndexWriterConfig.DEFAULT_TERM_INDEX_INTERVAL,
-                                               MergeState.CheckAbort.NONE, null, new FieldInfos.FieldNumbers(), codec, context);
+                                               MergeState.CheckAbort.NONE, null, new FieldInfos.FieldNumbers(), context);
 
       merger.add(r1);
       merger.add(r2);
diff --git a/lucene/core/src/test/org/apache/lucene/index/TestSegmentMerger.java b/lucene/core/src/test/org/apache/lucene/index/TestSegmentMerger.java
index 53918b3f31a..f2940b88272 100644
--- a/lucene/core/src/test/org/apache/lucene/index/TestSegmentMerger.java
+++ b/lucene/core/src/test/org/apache/lucene/index/TestSegmentMerger.java
@@ -80,7 +80,7 @@ public class TestSegmentMerger extends LuceneTestCase {
     final SegmentInfo si = new SegmentInfo(mergedDir, Constants.LUCENE_MAIN_VERSION, mergedSegment, 10000, -1, mergedSegment, false, null, false, codec, null, null);
 
     SegmentMerger merger = new SegmentMerger(si, InfoStream.getDefault(), mergedDir, IndexWriterConfig.DEFAULT_TERM_INDEX_INTERVAL,
-                                             MergeState.CheckAbort.NONE, null, new FieldInfos.FieldNumbers(), codec, newIOContext(random()));
+                                             MergeState.CheckAbort.NONE, null, new FieldInfos.FieldNumbers(), newIOContext(random()));
     merger.add(reader1);
     merger.add(reader2);
     MergeState mergeState = merger.merge();