diff --git a/net/decnet/dn_dev.c b/net/decnet/dn_dev.c
index 2f0ac3c3eb71..ba352588e344 100644
--- a/net/decnet/dn_dev.c
+++ b/net/decnet/dn_dev.c
@@ -152,7 +152,7 @@ static struct dn_dev_parms dn_dev_list[] =  {
 
 #define DN_DEV_LIST_SIZE ARRAY_SIZE(dn_dev_list)
 
-#define DN_DEV_PARMS_OFFSET(x) ((int) ((char *) &((struct dn_dev_parms *)0)->x))
+#define DN_DEV_PARMS_OFFSET(x) offsetof(struct dn_dev_parms, x)
 
 #ifdef CONFIG_SYSCTL