diff --git a/src/PanasonicProjectorController.cs b/src/PanasonicProjectorController.cs
index 461f2e2..c03dc0b 100644
--- a/src/PanasonicProjectorController.cs
+++ b/src/PanasonicProjectorController.cs
@@ -10,6 +10,9 @@
 using PepperDash.Essentials.Core.Queues;
 using PepperDash.Essentials.Core.Routing;
 using PepperDash.Essentials.Core.DeviceTypeInterfaces;
+#if SERIES4
+using TwoWayDisplayBase = PepperDash.Essentials.Devices.Common.Displays.TwoWayDisplayBase;
+#endif
 
 namespace PepperDash.Essentials.Plugins.Display.Panasonic.Projector
 {