diff --git a/lucene/CHANGES.txt b/lucene/CHANGES.txt
index 2cc172bd316..6e7690119d3 100644
--- a/lucene/CHANGES.txt
+++ b/lucene/CHANGES.txt
@@ -273,6 +273,8 @@ Optimizations
 
 * GITHUB#13431: Replace TreeMap and use compiled Patterns in Japanese UserDictionary. (Bruno Roustant)
 
+* GITHUB#12941: Don't preserve auxiliary buffer contents in LSBRadixSorter if it grows. (Stefan Vodita)
+
 Bug Fixes
 ---------------------
 (No changes)
diff --git a/lucene/core/src/java/org/apache/lucene/util/LSBRadixSorter.java b/lucene/core/src/java/org/apache/lucene/util/LSBRadixSorter.java
index 2b2c625a9ff..b1a53a966a0 100644
--- a/lucene/core/src/java/org/apache/lucene/util/LSBRadixSorter.java
+++ b/lucene/core/src/java/org/apache/lucene/util/LSBRadixSorter.java
@@ -92,7 +92,7 @@ public final class LSBRadixSorter {
       return;
     }
 
-    buffer = ArrayUtil.grow(buffer, len);
+    buffer = ArrayUtil.growNoCopy(buffer, len);
 
     int[] arr = array;