diff --git a/blockdev.c b/blockdev.c
index fc88dc0..25aaacf 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -2829,7 +2829,7 @@
 {
     BlockJob *job = NULL;
     BdrvDirtyBitmap *bmap = NULL;
-    BackupPerf perf = { .use_copy_range = true };
+    BackupPerf perf = { .use_copy_range = true, .max_workers = 64 };
     int job_flags = JOB_DEFAULT;
 
     if (!backup->has_speed) {
@@ -2858,6 +2858,12 @@
         if (backup->x_perf->has_use_copy_range) {
             perf.use_copy_range = backup->x_perf->use_copy_range;
         }
+        if (backup->x_perf->has_max_workers) {
+            perf.max_workers = backup->x_perf->max_workers;
+        }
+        if (backup->x_perf->has_max_chunk) {
+            perf.max_chunk = backup->x_perf->max_chunk;
+        }
     }
 
     if ((backup->sync == MIRROR_SYNC_MODE_BITMAP) ||