diff --git a/pkg/backup/create.go b/pkg/backup/create.go
index 1fbbe89a..786517f5 100644
--- a/pkg/backup/create.go
+++ b/pkg/backup/create.go
@@ -12,7 +12,7 @@ import (
 	"path"
 	"path/filepath"
 	"strings"
-	"sync"
+	"sync/atomic"
 	"time"
 
 	"github.com/Altinity/clickhouse-backup/pkg/clickhouse"
@@ -208,7 +208,7 @@ func (b *Backuper) createBackupLocal(ctx context.Context, backupName string, par
 				}
 				// more precise data size calculation
 				for _, size := range realSize {
-					backupDataSize += uint64(size)
+					atomic.AddUint64(&backupDataSize, uint64(size))
 				}
 			}
 			// https://github.com/Altinity/clickhouse-backup/issues/529
@@ -643,7 +643,6 @@ func (b *Backuper) AddTableToBackup(ctx context.Context, backupName, shadowBacku
 func (b *Backuper) uploadObjectDiskParts(ctx context.Context, backupName, backupShadowPath string, disk clickhouse.Disk) (int64, error) {
 	var size int64
 	var err error
-	var sizeMutex sync.Mutex
 	if err = object_disk.InitCredentialsAndConnections(ctx, b.ch, b.cfg, disk.Name); err != nil {
 		return 0, err
 	}
@@ -688,13 +687,11 @@ func (b *Backuper) uploadObjectDiskParts(ctx context.Context, backupName, backup
 				}
 				realSize += objSize
 			}
-			sizeMutex.Lock()
 			if realSize > objPartFileMeta.TotalSize {
-				size += realSize
+				atomic.AddInt64(&size, realSize)
 			} else {
-				size += objPartFileMeta.TotalSize
+				atomic.AddInt64(&size, objPartFileMeta.TotalSize)
 			}
-			sizeMutex.Unlock()
 			return nil
 		})
 		return nil
diff --git a/pkg/backup/restore.go b/pkg/backup/restore.go
index b2156c69..80a35aa1 100644
--- a/pkg/backup/restore.go
+++ b/pkg/backup/restore.go
@@ -17,7 +17,7 @@ import (
 	"path/filepath"
 	"regexp"
 	"strings"
-	"sync"
+	"sync/atomic"
 	"time"
 
 	"github.com/Altinity/clickhouse-backup/pkg/common"
@@ -850,7 +850,6 @@ func (b *Backuper) downloadObjectDiskParts(ctx context.Context, backupName strin
 			start := time.Now()
 			downloadObjectDiskPartsWorkingGroup, ctx := errgroup.WithContext(ctx)
 			downloadObjectDiskPartsWorkingGroup.SetLimit(int(b.cfg.General.DownloadConcurrency))
-			sizeMutex := sync.Mutex{}
 			for _, part := range parts {
 				partPath := path.Join(diskMap[diskName], "backup", backupName, "shadow", dbAndTableDir, diskName, part.Name)
 				walkErr := filepath.Walk(partPath, func(fPath string, fInfo fs.FileInfo, err error) error {
@@ -891,9 +890,7 @@ func (b *Backuper) downloadObjectDiskParts(ctx context.Context, backupName strin
 							if copiedSize, copyObjectErr := object_disk.CopyObject(ctx, b.ch, b.cfg, diskName, storageObject.ObjectSize, srcBucket, srcKey, storageObject.ObjectRelativePath); copyObjectErr != nil {
 								return fmt.Errorf("object_disk.CopyObject error: %v", err)
 							} else {
-								sizeMutex.Lock()
-								size += copiedSize
-								sizeMutex.Unlock()
+								atomic.AddInt64(&size, copiedSize)
 							}
 						}
 						return nil
diff --git a/pkg/storage/object_disk/object_disk.go b/pkg/storage/object_disk/object_disk.go
index c36b7bd5..21d94910 100644
--- a/pkg/storage/object_disk/object_disk.go
+++ b/pkg/storage/object_disk/object_disk.go
@@ -239,7 +239,6 @@ func InitCredentialsAndConnections(ctx context.Context, ch *clickhouse.ClickHous
 	var err error
 	var mu sync.Mutex
 	mu.Lock()
-	defer mu.Unlock()
 	if _, exists := DisksCredentials[diskName]; !exists {
 		DisksCredentials, err = getObjectDisksCredentials(ctx, ch)
 		if err != nil {
@@ -256,6 +255,7 @@ func InitCredentialsAndConnections(ctx context.Context, ch *clickhouse.ClickHous
 		}
 		DisksConnections[diskName] = *connection
 	}
+	mu.Unlock()
 	return nil
 }
 
diff --git a/pkg/storage/s3.go b/pkg/storage/s3.go
index 4f476a17..70324481 100644
--- a/pkg/storage/s3.go
+++ b/pkg/storage/s3.go
@@ -525,11 +525,11 @@ func (s *S3) CopyObject(ctx context.Context, srcSize int64, srcBucket, srcKey, d
 				return err
 			}
 			mu.Lock()
-			defer mu.Unlock()
 			parts = append(parts, s3types.CompletedPart{
 				ETag:       partResp.CopyPartResult.ETag,
 				PartNumber: aws.Int32(currentPartNumber),
 			})
+			mu.Unlock()
 			return nil
 		})
 	}