diff --git a/firmware/heater_control.h b/firmware/heater_control.h
index e67f023..7506052 100644
--- a/firmware/heater_control.h
+++ b/firmware/heater_control.h
@@ -8,6 +8,7 @@ enum class HeaterState
     WarmupRamp,
     ClosedLoop,
     Stopped,
+    NoHeaterSupply,
 };
 
 void StartHeaterControl();