diff --git a/wiringpi.i b/wiringpi.i
index c4e2f59..45b2b87 100644
--- a/wiringpi.i
+++ b/wiringpi.i
@@ -1,5 +1,7 @@
 %module wiringpi2
 
+%import "constants.i"
+
 %{
 #include "WiringPi/wiringPi/wiringPi.h"
 #include "WiringPi/wiringPi/wiringPiI2C.h"