diff --git a/net/sched/cls_flower.c b/net/sched/cls_flower.c
index 4b8dd37dd4f8..9aada2d0ef06 100644
--- a/net/sched/cls_flower.c
+++ b/net/sched/cls_flower.c
@@ -993,7 +993,7 @@ static int fl_init_mask_hashtable(struct fl_flow_mask *mask)
 }
 
 #define FL_KEY_MEMBER_OFFSET(member) offsetof(struct fl_flow_key, member)
-#define FL_KEY_MEMBER_SIZE(member) (sizeof(((struct fl_flow_key *) 0)->member))
+#define FL_KEY_MEMBER_SIZE(member) FIELD_SIZEOF(struct fl_flow_key, member)
 
 #define FL_KEY_IS_MASKED(mask, member)						\
 	memchr_inv(((char *)mask) + FL_KEY_MEMBER_OFFSET(member),		\