diff --git a/constants.py b/constants.py
index 75ce015..f501698 100644
--- a/constants.py
+++ b/constants.py
@@ -38,4 +38,10 @@ INT_EDGE_SETUP = 0;
 INT_EDGE_FALLING = 1;
 INT_EDGE_RISING = 2;
 INT_EDGE_BOTH = 3;
+
+# Shifting (from wiringShift.h)
+
+LSBFIRST = 0;
+MSBFIRST = 1;
+
 %}