diff --git a/include/linux/i2c-dev.h b/include/linux/i2c-dev.h
index 499522b..23f7c2c 100644
--- a/include/linux/i2c-dev.h
+++ b/include/linux/i2c-dev.h
@@ -25,6 +25,7 @@
 
 #include <linux/types.h>
 #include <sys/ioctl.h>
+#include <stddef.h>
 
 
 /* -- i2c.h -- */