diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index 3e6477c6082e..4dd8341225bc 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -3676,7 +3676,7 @@ static inline unsigned int xfrm_sa_len(struct xfrm_state *x)
 	}
 	if (x->if_id)
 		l += nla_total_size(sizeof(x->if_id));
-	if (x->pcpu_num)
+	if (x->pcpu_num != UINT_MAX)
 		l += nla_total_size(sizeof(x->pcpu_num));
 
 	/* Must count x->lastused as it may become non-zero behind our back. */