diff --git a/targets/arduino/WInterrupts.c b/targets/arduino/WInterrupts.c
index 63f5fea74..ff55c451f 100755
--- a/targets/arduino/WInterrupts.c
+++ b/targets/arduino/WInterrupts.c
@@ -26,6 +26,7 @@
 #include <inttypes.h>
 #include <avr/io.h>
 #include <avr/interrupt.h>
+#include <avr/signal.h>
 #include <avr/pgmspace.h>
 #include <stdio.h>