diff --git a/Firmware/Marlin_main.cpp b/Firmware/Marlin_main.cpp
index 3cd76496f..e59718cb3 100644
--- a/Firmware/Marlin_main.cpp
+++ b/Firmware/Marlin_main.cpp
@@ -244,7 +244,7 @@ uint8_t newFanSpeed = 0;
 	  bool powersupply = true;
   #endif
 
-bool cancel_heatup = false;
+static bool cancel_heatup = false;
 
 int8_t busy_state = NOT_BUSY;
 static long prev_busy_signal_ms = -1;
diff --git a/Firmware/ultralcd.h b/Firmware/ultralcd.h
index 5912ee0d5..8e85e9364 100755
--- a/Firmware/ultralcd.h
+++ b/Firmware/ultralcd.h
@@ -163,7 +163,6 @@ void printf_IRSensorAnalogBoardChange();
 
 extern int8_t SilentModeMenu;
 
-extern bool cancel_heatup;
 extern bool isPrintPaused;
 
 extern uint8_t scrollstuff;