From 9492f90b5c1714f9a76ef9b233ada7f1126894b5 Mon Sep 17 00:00:00 2001
From: Gordon Williams <gw@pur3.co.uk>
Date: Mon, 19 Feb 2018 15:34:14 +0000
Subject: [PATCH] f4 build

---
 targets/stm32/jshardware.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/targets/stm32/jshardware.c b/targets/stm32/jshardware.c
index c1c5ae901a..0b2f7aab5f 100644
--- a/targets/stm32/jshardware.c
+++ b/targets/stm32/jshardware.c
@@ -585,13 +585,13 @@ USART_TypeDef* getUsartFromDevice(IOEventFlags device) {
  switch (device) {
    case EV_SERIAL1 : return USART1;
    case EV_SERIAL2 : return USART2;
-#if USART_COUNT>=3
+#if USART_COUNT>=3 && defined(USART3)
    case EV_SERIAL3 : return USART3;
 #endif
-#if USART_COUNT>=4
+#if USART_COUNT>=4 && defined(UART4)
    case EV_SERIAL4 : return UART4;
 #endif
-#if USART_COUNT>=5
+#if USART_COUNT>=5 && defined(UART5)
    case EV_SERIAL5 : return UART5;
 #endif
 #if USART_COUNT>=6