diff --git a/fpga/zsbl/gpt.c b/fpga/zsbl/gpt.c
index 90948935b..c308ea878 100644
--- a/fpga/zsbl/gpt.c
+++ b/fpga/zsbl/gpt.c
@@ -1,5 +1,6 @@
 #include "gpt.h"
 #include "boot.h"
+#include "uart.h"
 #include <stddef.h>
 
 /* PSUEDOCODE