diff --git a/Software/src/inverter/KOSTAL-RS485.h b/Software/src/inverter/KOSTAL-RS485.h
index a14d5dca..19c4137d 100644
--- a/Software/src/inverter/KOSTAL-RS485.h
+++ b/Software/src/inverter/KOSTAL-RS485.h
@@ -43,6 +43,8 @@ class KostalInverterProtocol : public Rs485InverterProtocol {
   unsigned long currentMillis;
   unsigned long startupMillis = 0;
   unsigned long contactorMillis = 0;
+  unsigned long contactortestTimerStart = 0;
+  bool contactortestTimerActive = false;
 
   uint16_t rx_index = 0;
   bool RX_allow = false;