diff --git a/bootloader/mrobe500.c b/bootloader/mrobe500.c
index 3b2ede685a..50c2acb9bd 100755
--- a/bootloader/mrobe500.c
+++ b/bootloader/mrobe500.c
@@ -39,6 +39,7 @@
 #include "rbunicode.h"
 #include "usb.h"
 #include "spi-target.h"
+#include "uart-target.h"
 
 void main(void)
 {
diff --git a/firmware/target/arm/olympus/mrobe-500/uart-target.h b/firmware/target/arm/olympus/mrobe-500/uart-target.h
index 3b765d3ed8..b4e049f897 100644
--- a/firmware/target/arm/olympus/mrobe-500/uart-target.h
+++ b/firmware/target/arm/olympus/mrobe-500/uart-target.h
@@ -26,5 +26,6 @@ void uartSetup(void);
 void uartPuts(const char *str);
 void uartGets(char *str, unsigned int size);
 int  uartPollch(unsigned int ticks);
+void uartHeartbeat(void);
 
 #endif