diff --git a/energy_control b/energy_control
index 983a9bd..11f7101 100644
--- a/energy_control
+++ b/energy_control
@@ -57,9 +57,12 @@ function draw_screen()
         if redstone_toggle_state == true then
             term.setBackgroundColor(colors.green)
             term.write('On')
-        else
+        elseif redstone_toggle_state == false then
             term.setBackgroundColor(colors.red)
             term.write('Off')
+        elseif redstone_toggle_state == nil then
+            term.setBackgroundColor(colors.purple)
+            term.write('Unknown')
         end
         print()
         term.setBackgroundColor(colors.black)