diff --git a/pkg/config/json.go b/pkg/config/json.go
index 580785cb..1452e3b6 100644
--- a/pkg/config/json.go
+++ b/pkg/config/json.go
@@ -16,14 +16,15 @@ const (
 	linuxBootloader vmComponentKind = "linuxBootloader"
 
 	// VirtIO device kinds
-	vfNet    vmComponentKind = "virtionet"
-	vfVsock  vmComponentKind = "virtiosock"
-	vfBlk    vmComponentKind = "virtioblk"
-	vfFs     vmComponentKind = "virtiofs"
-	vfRng    vmComponentKind = "virtiorng"
-	vfSerial vmComponentKind = "virtioserial"
-	vfGpu    vmComponentKind = "virtiogpu"
-	vfInput  vmComponentKind = "virtioinput"
+	vfNet          vmComponentKind = "virtionet"
+	vfVsock        vmComponentKind = "virtiosock"
+	vfBlk          vmComponentKind = "virtioblk"
+	vfFs           vmComponentKind = "virtiofs"
+	vfRng          vmComponentKind = "virtiorng"
+	vfSerial       vmComponentKind = "virtioserial"
+	vfGpu          vmComponentKind = "virtiogpu"
+	vfInput        vmComponentKind = "virtioinput"
+	usbMassStorage vmComponentKind = "usbmassstorage"
 )
 
 type jsonKind struct {
@@ -123,6 +124,10 @@ func unmarshalDevice(rawMsg json.RawMessage) (VirtioDevice, error) {
 		var newDevice VirtioInput
 		err = json.Unmarshal(rawMsg, &newDevice)
 		dev = &newDevice
+	case usbMassStorage:
+		var newDevice USBMassStorage
+		err = json.Unmarshal(rawMsg, &newDevice)
+		dev = &newDevice
 	default:
 		return nil, fmt.Errorf("unknown 'kind' field: '%s'", kind)
 	}
@@ -287,3 +292,14 @@ func (dev *VirtioInput) MarshalJSON() ([]byte, error) {
 		VirtioInput: *dev,
 	})
 }
+
+func (dev *USBMassStorage) MarshalJSON() ([]byte, error) {
+	type devWithKind struct {
+		jsonKind
+		USBMassStorage
+	}
+	return json.Marshal(devWithKind{
+		jsonKind:       kind(usbMassStorage),
+		USBMassStorage: *dev,
+	})
+}
diff --git a/pkg/config/json_test.go b/pkg/config/json_test.go
index a0cface1..ad9cb213 100644
--- a/pkg/config/json_test.go
+++ b/pkg/config/json_test.go
@@ -102,15 +102,14 @@ var jsonTests = map[string]jsonTest{
 			err = vm.AddDevice(dev)
 			require.NoError(t, err)
 			// USB mass storage
-			//dev, err = USBMassStorageNew("/usbmassstorage")
-			//require.NoError(t, err)
-			//err = vm.AddDevice(dev)
-			//require.NoError(t, err)
+			dev, err = USBMassStorageNew("/usbmassstorage")
+			require.NoError(t, err)
+			err = vm.AddDevice(dev)
+			require.NoError(t, err)
 
 			return vm
 		},
-		//expectedJSON: `{"vcpus":3,"memoryBytes":4000000000,"bootloader":{"kind":"linuxBootloader","VmlinuzPath":"/vmlinuz","KernelCmdLine":"/initrd","InitrdPath":"console=hvc0"},"devices":[{"kind":"virtioserial","LogFile":"/virtioserial","UsesStdio":false},{"inputType":"keyboard"},{"usesGUI":false,"height":800,"width":600},{"kind":"virtionet","Nat":true,"MacAddress":"ABEiM0RV","Socket":null,"UnixSocketPath":""},{"kind":"virtiorng"},{"kind":"virtioblk","DevName":"virtio-blk","ImagePath":"/virtioblk","ReadOnly":false,"DeviceIdentifier":""},{"kind":"virtiosock","Port":1234,"SocketURL":"/virtiovsock","Listen":false},{"kind":"virtiofs","SharedDir":"/virtiofs","MountTag":"tag"},{"DevName":"usb-mass-storage","ImagePath":"/usbmassstorage","ReadOnly":false}]}`,
-		expectedJSON: `{"vcpus":3,"memoryBytes":4000000000,"bootloader":{"kind":"linuxBootloader","VmlinuzPath":"/vmlinuz","KernelCmdLine":"/initrd","InitrdPath":"console=hvc0"},"devices":[{"kind":"virtioserial","LogFile":"/virtioserial","UsesStdio":false},{"kind":"virtioinput","inputType":"keyboard"},{"kind":"virtiogpu","usesGUI":false,"height":800,"width":600},{"kind":"virtionet","Nat":true,"MacAddress":"ABEiM0RV","Socket":null,"UnixSocketPath":""},{"kind":"virtiorng"},{"kind":"virtioblk","DevName":"virtio-blk","ImagePath":"/virtioblk","ReadOnly":false,"DeviceIdentifier":""},{"kind":"virtiosock","Port":1234,"SocketURL":"/virtiovsock","Listen":false},{"kind":"virtiofs","SharedDir":"/virtiofs","MountTag":"tag"}]}`,
+		expectedJSON: `{"vcpus":3,"memoryBytes":4000000000,"bootloader":{"kind":"linuxBootloader","VmlinuzPath":"/vmlinuz","KernelCmdLine":"/initrd","InitrdPath":"console=hvc0"},"devices":[{"kind":"virtioserial","LogFile":"/virtioserial","UsesStdio":false},{"kind":"virtioinput","inputType":"keyboard"},{"kind":"virtiogpu","usesGUI":false,"height":800,"width":600},{"kind":"virtionet","Nat":true,"MacAddress":"ABEiM0RV","Socket":null,"UnixSocketPath":""},{"kind":"virtiorng"},{"kind":"virtioblk","DevName":"virtio-blk","ImagePath":"/virtioblk","ReadOnly":false,"DeviceIdentifier":""},{"kind":"virtiosock","Port":1234,"SocketURL":"/virtiovsock","Listen":false},{"kind":"virtiofs","SharedDir":"/virtiofs","MountTag":"tag"},{"kind":"usbmassstorage","DevName":"usb-mass-storage","ImagePath":"/usbmassstorage","ReadOnly":false}]}`,
 	},
 }