diff --git a/internal/backend/disk/disk.go b/internal/backend/disk/disk.go
index 52b0965..907747d 100644
--- a/internal/backend/disk/disk.go
+++ b/internal/backend/disk/disk.go
@@ -3,6 +3,7 @@ package disk
 
 import (
 	"encoding/json"
+	"fmt"
 	"os"
 	"path/filepath"
 	"time"
@@ -64,24 +65,22 @@ type Backend struct {
 
 // New creates a new disk backend instance
 func New(cfg config.DiskConfig, logger *zap.Logger) (*Backend, error) {
-	rootDir := cfg.RootDir
-	if rootDir == "" {
-		// Default to a temp directory if not specified
-		rootDir = filepath.Join(os.TempDir(), "variobjectstorage")
+	if cfg.RootDir == "" {
+		return nil, fmt.Errorf("disk backend requires root_dir to be configured")
 	}
 
 	// Ensure root directory exists
-	if err := os.MkdirAll(rootDir, dirPermissions); err != nil {
+	if err := os.MkdirAll(cfg.RootDir, dirPermissions); err != nil {
 		return nil, err
 	}
 
 	// Ensure locks directory exists
-	if err := os.MkdirAll(filepath.Join(rootDir, locksDir), dirPermissions); err != nil {
+	if err := os.MkdirAll(filepath.Join(cfg.RootDir, locksDir), dirPermissions); err != nil {
 		return nil, err
 	}
 
 	return &Backend{
-		rootDir: rootDir,
+		rootDir: cfg.RootDir,
 		logger:  logger.With(zap.String("backend", "disk")),
 	}, nil
 }