diff --git a/supfile.go b/supfile.go
index ad5e924..1cde8f5 100644
--- a/supfile.go
+++ b/supfile.go
@@ -86,9 +86,9 @@ func NewSupfile(file string) (*Supfile, error) {
 			if cmd.Local != "" {
 				return nil, errors.New("command.local is not supported in Supfile v" + conf.Version)
 			}
-			// if cmd.Serial != 0 {
-			// 	return nil, errors.New("command.serial is not supported in Supfile v0.2")
-			// }
+			if cmd.Serial != 0 {
+				return nil, errors.New("command.serial is not supported in Supfile v" + conf.Version)
+			}
 		}
 		for _, network := range conf.Networks {
 			if network.Inventory != "" {
diff --git a/task.go b/task.go
index af2849a..ec055c0 100644
--- a/task.go
+++ b/task.go
@@ -19,17 +19,28 @@ func CreateTasks(cmd *Command, clients []Client, env string) ([]*Task, error) {
 
 	// Anything to upload?
 	for _, upload := range cmd.Upload {
-		task := &Task{
+		task := Task{
 			Run:   RemoteTarCommand(upload.Dst),
 			Input: NewTarStreamReader(upload.Src, upload.Exc, env),
 		}
 
-		if cmd.RunOnce {
+		if cmd.Once {
 			task.Clients = []Client{clients[0]}
-			tasks = append(tasks, task)
+			tasks = append(tasks, &task)
+		} else if cmd.Serial > 0 {
+			// Each "serial" task client group is executed sequentially.
+			for i := 0; i < len(clients); i += cmd.Serial {
+				j := i + cmd.Serial
+				if j > len(clients) {
+					j = len(clients)
+				}
+				copy := task
+				copy.Clients = clients[i:j]
+				tasks = append(tasks, &copy)
+			}
 		} else {
 			task.Clients = clients
-			tasks = append(tasks, task)
+			tasks = append(tasks, &task)
 		}
 	}
 
@@ -44,18 +55,30 @@ func CreateTasks(cmd *Command, clients []Client, env string) ([]*Task, error) {
 			return nil, err
 		}
 
-		task := &Task{
+		task := Task{
 			Run: string(data),
 		}
 		if cmd.Stdin {
 			task.Input = os.Stdin
 		}
-		if cmd.RunOnce {
+		if cmd.Once {
 			task.Clients = []Client{clients[0]}
+			tasks = append(tasks, &task)
+		} else if cmd.Serial > 0 {
+			// Each "serial" task client group is executed sequentially.
+			for i := 0; i < len(clients); i += cmd.Serial {
+				j := i + cmd.Serial
+				if j > len(clients) {
+					j = len(clients)
+				}
+				copy := task
+				copy.Clients = clients[i:j]
+				tasks = append(tasks, &copy)
+			}
 		} else {
 			task.Clients = clients
+			tasks = append(tasks, &task)
 		}
-		tasks = append(tasks, task)
 	}
 
 	// Local command.
@@ -82,7 +105,7 @@ func CreateTasks(cmd *Command, clients []Client, env string) ([]*Task, error) {
 		if cmd.Stdin {
 			task.Input = os.Stdin
 		}
-		if cmd.RunOnce {
+		if cmd.Once {
 			task.Clients = []Client{clients[0]}
 			tasks = append(tasks, &task)
 		} else if cmd.Serial > 0 {