@@ -60,7 +60,7 @@ func NewDaemon(t *testing.T) *Daemon {

 }

 // Start will start the daemon and return once it is ready to receive requests.

-// You can specify additional daemon flags (e.g. "--restart=false").

+// You can specify additional daemon flags.

 func (d *Daemon) Start(arg ...string) error {

 	dockerBinary, err := exec.LookPath(dockerBinary)

 	if err != nil {

@@ -71,10 +71,15 @@ func (d *Daemon) Start(arg ...string) error {

 		"--host", d.sock(),

 		"--daemon", "--debug",

 		"--graph", fmt.Sprintf("%s/graph", d.folder),

-		"--storage-driver", d.storageDriver,

-		"--exec-driver", d.execDriver,

 		"--pidfile", fmt.Sprintf("%s/docker.pid", d.folder),

 	}

+	if d.storageDriver != "" {

+		args = append(args, "--storage-driver", d.storageDriver)

+	}

+	if d.execDriver != "" {

+		args = append(args, "--exec-driver", d.execDriver)

+	}

+

 	args = append(args, arg...)

 	d.cmd = exec.Command(dockerBinary, args...)