diff --git a/cubesatsim/cubesatsim.h b/cubesatsim/cubesatsim.h
index e362968c..d096c1b6 100644
--- a/cubesatsim/cubesatsim.h
+++ b/cubesatsim/cubesatsim.h
@@ -276,6 +276,7 @@ unsigned long pb_press_start;
 
 bool TimerHandler0(struct repeating_timer *t);
 RPI_PICO_Timer ITimer0(0);
+long micro_timer;
 
 /*
  * TelemEncoding.h