diff --git a/internal/chunk/control/workers.go b/internal/chunk/control/workers.go
index d0e614f8..16254e52 100644
--- a/internal/chunk/control/workers.go
+++ b/internal/chunk/control/workers.go
@@ -11,14 +11,18 @@ import (
 	"github.com/rusq/slackdump/v2/internal/chunk/processor/dirproc"
 	"github.com/rusq/slackdump/v2/internal/chunk/transform"
 	"github.com/rusq/slackdump/v2/logger"
+	"github.com/slack-go/slack"
 )
 
 func userWorker(ctx context.Context, s Streamer, chunkdir *chunk.Directory, tf TransformStarter) error {
-	userproc, err := dirproc.NewUsers(chunkdir)
+	var users = make([]slack.User, 0, 100)
+	userproc, err := dirproc.NewUsers(chunkdir, dirproc.WithUsers(func(us []slack.User) error {
+		users = append(users, us...)
+		return nil
+	}))
 	if err != nil {
 		return err
 	}
-
 	if err := s.Users(ctx, userproc); err != nil {
 		if err2 := userproc.Close(); err2 != nil {
 			err = errors.Join(err2)
@@ -29,9 +33,8 @@ func userWorker(ctx context.Context, s Streamer, chunkdir *chunk.Directory, tf T
 		return fmt.Errorf("error closing user processor: %w", err)
 	}
 	logger.FromContext(ctx).Debug("users done")
-	users, err := chunkdir.Users() // load users from chunks
-	if err != nil {
-		return fmt.Errorf("error loading users: %w", err)
+	if len(users) == 0 {
+		return fmt.Errorf("unable to proceed, no users found")
 	}
 	if err := tf.StartWithUsers(ctx, users); err != nil {
 		return fmt.Errorf("error starting the transformer: %w", err)
diff --git a/internal/chunk/processor/dirproc/users.go b/internal/chunk/processor/dirproc/users.go
index a3ae6311..b31ee9ee 100644
--- a/internal/chunk/processor/dirproc/users.go
+++ b/internal/chunk/processor/dirproc/users.go
@@ -1,17 +1,52 @@
 package dirproc
 
-import "github.com/rusq/slackdump/v2/internal/chunk"
+import (
+	"context"
+	"fmt"
+
+	"github.com/rusq/slackdump/v2/internal/chunk"
+	"github.com/rusq/slackdump/v2/internal/chunk/processor"
+	"github.com/slack-go/slack"
+)
 
 // Users is a users processor.
 type Users struct {
 	*baseproc
+	cb func([]slack.User) error
+}
+
+var _ processor.Users = &Users{}
+
+type UserOption func(*Users)
+
+// WithUsers sets the users callback.
+func WithUsers(cb func([]slack.User) error) UserOption {
+	return func(u *Users) {
+		u.cb = cb
+	}
 }
 
 // NewUsers creates a new Users processor.
-func NewUsers(cd *chunk.Directory) (*Users, error) {
+func NewUsers(cd *chunk.Directory, opt ...UserOption) (*Users, error) {
 	p, err := newBaseProc(cd, "users")
 	if err != nil {
 		return nil, err
 	}
-	return &Users{baseproc: p}, nil
+	u := &Users{baseproc: p}
+	for _, o := range opt {
+		o(u)
+	}
+	return u, nil
+}
+
+func (u *Users) Users(ctx context.Context, users []slack.User) error {
+	if err := u.baseproc.Users(ctx, users); err != nil {
+		return err
+	}
+	if u.cb != nil {
+		if err := u.cb(users); err != nil {
+			return fmt.Errorf("users callback: %w", err)
+		}
+	}
+	return nil
 }