diff --git a/app/src/main/java/com/geeksville/mesh/android/ContextServices.kt b/app/src/main/java/com/geeksville/mesh/android/ContextServices.kt
index 511ba1324..970dcdd51 100644
--- a/app/src/main/java/com/geeksville/mesh/android/ContextServices.kt
+++ b/app/src/main/java/com/geeksville/mesh/android/ContextServices.kt
@@ -9,4 +9,4 @@ import android.hardware.usb.UsbManager
  */
 val Context.bluetoothManager: BluetoothManager? get() = getSystemService(Context.BLUETOOTH_SERVICE) as? BluetoothManager?
 
-val Context.usbManager: UsbManager get() = requireNotNull(getSystemService(Context.USB_SERVICE) as? UsbManager) { "USB_SERVICE is not available"}
+val Context.usbManager: UsbManager get() = requireNotNull(getSystemService(Context.USB_SERVICE) as? UsbManager?) { "USB_SERVICE is not available"}