diff --git a/CHANGELOG.md b/CHANGELOG.md
index 3103208e..40d86d91 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -15,6 +15,7 @@ Changelog for FrostFS Node
 - `common.PrintVerbose` prints via `cobra.Command.Printf` (#1962)
 - Env prefix in configuration changed to `FROSTFS_*` (#43)
 - Link object is broadcast throughout the whole container now (#57)
+- Pilorama now can merge multiple batches into one (#2231)
 
 ### Fixed
 - Increase payload size metric on shards' `put` operation (#1794)
diff --git a/pkg/local_object_storage/pilorama/batch.go b/pkg/local_object_storage/pilorama/batch.go
index 59712b76..43375ba1 100644
--- a/pkg/local_object_storage/pilorama/batch.go
+++ b/pkg/local_object_storage/pilorama/batch.go
@@ -10,8 +10,11 @@ import (
 )
 
 type batch struct {
-	forest     *boltForest
-	timer      *time.Timer
+	forest *boltForest
+	timer  *time.Timer
+	// mtx protects timer and operations fields.
+	// Because mtx can be taken inside a transaction,
+	// transactions MUST NOT be executed with the mutex taken to avoid a deadlock.
 	mtx        sync.Mutex
 	start      sync.Once
 	cid        cidSDK.ID
@@ -24,16 +27,12 @@ func (b *batch) trigger() {
 	b.mtx.Lock()
 	if b.timer != nil {
 		b.timer.Stop()
-		b.timer = nil
 	}
 	b.mtx.Unlock()
 	b.start.Do(b.run)
 }
 
 func (b *batch) run() {
-	sort.Slice(b.operations, func(i, j int) bool {
-		return b.operations[i].Time < b.operations[j].Time
-	})
 	fullID := bucketName(b.cid, b.treeID)
 	err := b.forest.db.Update(func(tx *bbolt.Tx) error {
 		bLog, bTree, err := b.forest.getTreeBuckets(tx, fullID)
@@ -41,6 +40,16 @@ func (b *batch) run() {
 			return err
 		}
 
+		b.mtx.Lock()
+		b.timer = nil
+		b.mtx.Unlock()
+
+		// Sorting without a mutex is ok, because we append to this slice only if timer is non-nil.
+		// See (*boltForest).addBatch for details.
+		sort.Slice(b.operations, func(i, j int) bool {
+			return b.operations[i].Time < b.operations[j].Time
+		})
+
 		var lm Move
 		return b.forest.applyOperation(bLog, bTree, b.operations, &lm)
 	})
diff --git a/pkg/local_object_storage/pilorama/boltdb.go b/pkg/local_object_storage/pilorama/boltdb.go
index 0f546ef6..247d07d2 100644
--- a/pkg/local_object_storage/pilorama/boltdb.go
+++ b/pkg/local_object_storage/pilorama/boltdb.go
@@ -377,7 +377,9 @@ func (t *boltForest) addBatch(d CIDDescriptor, treeID string, m *Move, ch chan e
 		results:    []chan<- error{ch},
 		operations: []*Move{m},
 	}
+	b.mtx.Lock()
 	b.timer = time.AfterFunc(t.db.MaxBatchDelay, b.trigger)
+	b.mtx.Unlock()
 	t.batches = append(t.batches, b)
 	t.mtx.Unlock()
 }