diff --git a/STM32/cores/arduino/util/delay.h b/STM32/cores/arduino/util/delay.h
new file mode 100644
index 0000000..4abb998
--- /dev/null
+++ b/STM32/cores/arduino/util/delay.h
@@ -0,0 +1,5 @@
+//AVR compatibility functions
+
+#define _delay_us(n) delayMicroseconds(n)
+
+#define _delay_ms(n) delay(n)