diff --git a/cubesatsim/cubesatsim.h b/cubesatsim/cubesatsim.h
index 62a0b95c..92fd67c9 100644
--- a/cubesatsim/cubesatsim.h
+++ b/cubesatsim/cubesatsim.h
@@ -303,7 +303,7 @@ int mode_count = 0;
 unsigned long pb_press_start;
 
 bool TimerHandler0(struct repeating_timer *t);
-RPI_PICO_Timer ITimer0(0);
+global RPI_PICO_Timer ITimer0(0);
 RPI_PICO_Timer ITimer1(1);
 bool timer0_on = false;