diff --git a/src/libmodbus/modbus.c b/src/libmodbus/modbus.c
index 2cdf985..af3b240 100644
--- a/src/libmodbus/modbus.c
+++ b/src/libmodbus/modbus.c
@@ -50,6 +50,11 @@
 #define ENOTSUP 134
 #endif
 
+/* workaround for stm32duino delay and delayMicroseconds */
+#ifdef ARDUINO_ARCH_STM32
+#include <wiring_time.h>
+#endif
+
 #include "modbus.h"
 #include "modbus-private.h"