diff --git a/cubesatsim/cubesatsim.h b/cubesatsim/cubesatsim.h
index 69b6ebe7..d83b8e5c 100644
--- a/cubesatsim/cubesatsim.h
+++ b/cubesatsim/cubesatsim.h
@@ -203,6 +203,7 @@ void get_serial_clear_buffer();
 void set_lat_lon();
 void program_radio();
 void read_config_file(); 
+void write_config_file(); 
   
 #ifndef STASSID
 #define STASSID "Pico"