diff --git a/src/display.cpp b/src/display.cpp
index 94fd73f..1062a09 100644
--- a/src/display.cpp
+++ b/src/display.cpp
@@ -7,6 +7,7 @@
 #include <wifi.h>
 #include "hal.h"
 #include "power.h"
+#include "mailbox.h"
 
 SSD1306Wire *display;
 bool initOK = false;