diff --git a/lib/sectorbuilder/mock.go b/lib/sectorbuilder/mock.go
index 1433d6a2d..20ec4ac51 100644
--- a/lib/sectorbuilder/mock.go
+++ b/lib/sectorbuilder/mock.go
@@ -24,12 +24,6 @@ func TempSectorbuilder(sectorSize uint64) (*SectorBuilder, func(), error) {
 	staging := filepath.Join(dir, "staging")
 	cache := filepath.Join(dir, "cache")
 
-	for _, dir := range []string{metadata, sealed, staging, cache} {
-		if err := os.Mkdir(dir, 0755); err != nil {
-			return nil, nil, err
-		}
-	}
-
 	sb, err := New(&Config{
 		SectorSize: sectorSize,
 
diff --git a/lib/sectorbuilder/sectorbuilder.go b/lib/sectorbuilder/sectorbuilder.go
index 9944429ec..98e0dcfd1 100644
--- a/lib/sectorbuilder/sectorbuilder.go
+++ b/lib/sectorbuilder/sectorbuilder.go
@@ -2,6 +2,7 @@ package sectorbuilder
 
 import (
 	"io"
+	"os"
 	"sort"
 	"unsafe"
 
@@ -71,6 +72,15 @@ func New(cfg *Config) (*SectorBuilder, error) {
 
 	proverId := addressToProverID(cfg.Miner)
 
+	for _, dir := range []string{cfg.StagedDir, cfg.SealedDir, cfg.CacheDir, cfg.MetadataDir} {
+		if err := os.Mkdir(dir, 0755); err != nil {
+			if os.IsExist(err) {
+				continue
+			}
+			return nil, err
+		}
+	}
+
 	sbp, err := sectorbuilder.InitSectorBuilder(cfg.SectorSize, PoRepProofPartitions, 0, cfg.MetadataDir, proverId, cfg.SealedDir, cfg.StagedDir, cfg.CacheDir, 16, cfg.WorkerThreads)
 	if err != nil {
 		return nil, err