diff --git a/cubesatsim/cubesatsim.h b/cubesatsim/cubesatsim.h
index 9ad25fe0..4bdcb82c 100644
--- a/cubesatsim/cubesatsim.h
+++ b/cubesatsim/cubesatsim.h
@@ -137,6 +137,8 @@
 #define PAYLOAD_CLEAR 3
 
 volatile int prompt = false;
+volatile int prompting = false;
+
 char serial_string[128];
 
 float get_cpu_temp();