diff --git a/firmware/ice40-riscv/icE1usb/fw_app.c b/firmware/ice40-riscv/icE1usb/fw_app.c
index cb4dbb8..882e0ca 100644
--- a/firmware/ice40-riscv/icE1usb/fw_app.c
+++ b/firmware/ice40-riscv/icE1usb/fw_app.c
@@ -20,6 +20,7 @@
 #include "misc.h"
 #include "mini-printf.h"
 #include "spi.h"
+#include "usb_e1.h"
 #include "utils.h"