diff --git a/Firmware/fibre/cpp/include/fibre/protocol.hpp b/Firmware/fibre/cpp/include/fibre/protocol.hpp
index 89091f74..1fbecea0 100644
--- a/Firmware/fibre/cpp/include/fibre/protocol.hpp
+++ b/Firmware/fibre/cpp/include/fibre/protocol.hpp
@@ -12,6 +12,7 @@ see protocol.md for the protocol specification
 #include <limits>
 #include <cmath>
 //#include <stdint.h>
+#include <stdio.h>
 #include <string.h>
 #include "crc.hpp"
 #include "cpp_utils.hpp"