diff --git a/delay.h b/delay.h
index b044839..81bb705 100644
--- a/delay.h
+++ b/delay.h
@@ -1,6 +1,8 @@
 #ifndef	_DELAY_H
 #define	_DELAY_H
 
+#include	<stdint.h>
+
 // microsecond delay, does NOT reset WDT if feature enabled
 void delay_us(uint16_t delay);