diff --git a/firmware/ice40-riscv/e1-tracer/fw_app.c b/firmware/ice40-riscv/e1-tracer/fw_app.c
index c764b2e..3ddbf50 100644
--- a/firmware/ice40-riscv/e1-tracer/fw_app.c
+++ b/firmware/ice40-riscv/e1-tracer/fw_app.c
@@ -18,15 +18,12 @@
 #include "misc.h"
 #include "mini-printf.h"
 #include "spi.h"
+#include "usb_e1.h"
 #include "utils.h"
 
 
 extern const struct usb_stack_descriptors app_stack_desc;
 
-void usb_e1_init(void);
-void usb_e1_run(void);
-
-
 static void
 serial_no_init()
 {
diff --git a/firmware/ice40-riscv/e1-tracer/usb_e1.h b/firmware/ice40-riscv/e1-tracer/usb_e1.h
new file mode 100644
index 0000000..a573b38
--- /dev/null
+++ b/firmware/ice40-riscv/e1-tracer/usb_e1.h
@@ -0,0 +1,11 @@
+/*
+ * usb_e1.h
+ *
+ * Copyright (C) 2019-2020  Sylvain Munaut <tnt@246tNt.com>
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#pragma once
+
+void usb_e1_run(void);
+void usb_e1_init(void);