diff --git a/lib/mergeset/table.go b/lib/mergeset/table.go
index a5f3793b7..6f21b81f3 100644
--- a/lib/mergeset/table.go
+++ b/lib/mergeset/table.go
@@ -295,17 +295,18 @@ func (ris *rawItemsShard) updateFlushDeadline() {
 var tooLongItemLogger = logger.WithThrottler("tooLongItem", 5*time.Second)
 
 type partWrapper struct {
+	// refCount is the number of references to partWrapper
+	refCount atomic.Int32
+
+	// mustDrop marks partWrapper for deletion.
+	// This field should be updated only after partWrapper
+	// was removed from the list of active parts.
+	mustDrop atomic.Bool
+
 	p *part
 
 	mp *inmemoryPart
 
-	refCount uint32
-
-	// mustBeDeleted marks partWrapper for deletion.
-	// This field should be updated only after partWrapper
-	// was removed from the list of active parts.
-	mustBeDeleted uint32
-
 	isInMerge bool
 
 	// The deadline when the in-memory part must be flushed to disk.
@@ -313,20 +314,20 @@ type partWrapper struct {
 }
 
 func (pw *partWrapper) incRef() {
-	atomic.AddUint32(&pw.refCount, 1)
+	pw.refCount.Add(1)
 }
 
 func (pw *partWrapper) decRef() {
-	n := atomic.AddUint32(&pw.refCount, ^uint32(0))
-	if int32(n) < 0 {
-		logger.Panicf("BUG: pw.refCount must be bigger than 0; got %d", int32(n))
+	n := pw.refCount.Add(-1)
+	if n < 0 {
+		logger.Panicf("BUG: pw.refCount must be bigger than 0; got %d", n)
 	}
 	if n > 0 {
 		return
 	}
 
 	deletePath := ""
-	if pw.mp == nil && atomic.LoadUint32(&pw.mustBeDeleted) != 0 {
+	if pw.mp == nil && pw.mustDrop.Load() {
 		deletePath = pw.p.path
 	}
 	if pw.mp != nil {
@@ -611,7 +612,7 @@ func (tb *Table) UpdateMetrics(m *TableMetrics) {
 		m.InmemoryBlocksCount += p.ph.blocksCount
 		m.InmemoryItemsCount += p.ph.itemsCount
 		m.InmemorySizeBytes += p.size
-		m.PartsRefCount += uint64(atomic.LoadUint32(&pw.refCount))
+		m.PartsRefCount += uint64(pw.refCount.Load())
 	}
 
 	m.FilePartsCount += uint64(len(tb.fileParts))
@@ -620,7 +621,7 @@ func (tb *Table) UpdateMetrics(m *TableMetrics) {
 		m.FileBlocksCount += p.ph.blocksCount
 		m.FileItemsCount += p.ph.itemsCount
 		m.FileSizeBytes += p.size
-		m.PartsRefCount += uint64(atomic.LoadUint32(&pw.refCount))
+		m.PartsRefCount += uint64(pw.refCount.Load())
 	}
 	tb.partsLock.Unlock()
 
@@ -1035,12 +1036,13 @@ func (tb *Table) mustMergeIntoInmemoryPart(bsrs []*blockStreamReader, flushToDis
 
 func newPartWrapperFromInmemoryPart(mp *inmemoryPart, flushToDiskDeadline time.Time) *partWrapper {
 	p := mp.NewPart()
-	return &partWrapper{
+	pw := &partWrapper{
 		p:                   p,
 		mp:                  mp,
-		refCount:            1,
 		flushToDiskDeadline: flushToDiskDeadline,
 	}
+	pw.incRef()
+	return pw
 }
 
 func getMaxInmemoryPartSize() uint64 {
@@ -1340,9 +1342,9 @@ func (tb *Table) openCreatedPart(pws []*partWrapper, mpNew *inmemoryPart, dstPar
 	// Open the created part from disk.
 	pNew := mustOpenFilePart(dstPartPath)
 	pwNew := &partWrapper{
-		p:        pNew,
-		refCount: 1,
+		p: pNew,
 	}
+	pwNew.incRef()
 	return pwNew
 }
 
@@ -1408,7 +1410,7 @@ func (tb *Table) swapSrcWithDstParts(pws []*partWrapper, pwNew *partWrapper, dst
 	// Mark old parts as must be deleted and decrement reference count,
 	// so they are eventually closed and deleted.
 	for _, pw := range pws {
-		atomic.StoreUint32(&pw.mustBeDeleted, 1)
+		pw.mustDrop.Store(true)
 		pw.decRef()
 	}
 }
@@ -1513,9 +1515,9 @@ func mustOpenParts(path string) []*partWrapper {
 		partPath := filepath.Join(path, partName)
 		p := mustOpenFilePart(partPath)
 		pw := &partWrapper{
-			p:        p,
-			refCount: 1,
+			p: p,
 		}
+		pw.incRef()
 		pws = append(pws, pw)
 	}
 	partNamesPath := filepath.Join(path, partsFilename)