diff --git a/firmware/esp32/include/main.hpp b/firmware/esp32/include/main.hpp
new file mode 100644
index 0000000..1433a50
--- /dev/null
+++ b/firmware/esp32/include/main.hpp
@@ -0,0 +1,9 @@
+   #ifdef __cplusplus
+   extern "C" {
+   #endif
+
+   extern volatile bool criticalErrorFlag;
+
+   #ifdef __cplusplus
+   }
+   #endif