diff --git a/include/uapi/linux/netfilter/nf_log.h b/include/uapi/linux/netfilter/nf_log.h
index 8be21e02387d..d0b5fa91ff54 100644
--- a/include/uapi/linux/netfilter/nf_log.h
+++ b/include/uapi/linux/netfilter/nf_log.h
@@ -9,4 +9,6 @@
 #define NF_LOG_MACDECODE	0x20	/* Decode MAC header */
 #define NF_LOG_MASK		0x2f
 
+#define NF_LOG_PREFIXLEN	128
+
 #endif /* _NETFILTER_NF_LOG_H */
diff --git a/net/netfilter/nf_log.c b/net/netfilter/nf_log.c
index 3dca90dc24ad..ffb9e8ada899 100644
--- a/net/netfilter/nf_log.c
+++ b/net/netfilter/nf_log.c
@@ -13,7 +13,6 @@
 /* Internal logging interface, which relies on the real
    LOG target modules */
 
-#define NF_LOG_PREFIXLEN		128
 #define NFLOGGER_NAME_LEN		64
 
 static struct nf_logger __rcu *loggers[NFPROTO_NUMPROTO][NF_LOG_TYPE_MAX] __read_mostly;
diff --git a/net/netfilter/nft_log.c b/net/netfilter/nft_log.c
index 6271e40a3dd6..6f6e64423643 100644
--- a/net/netfilter/nft_log.c
+++ b/net/netfilter/nft_log.c
@@ -39,7 +39,8 @@ static void nft_log_eval(const struct nft_expr *expr,
 
 static const struct nla_policy nft_log_policy[NFTA_LOG_MAX + 1] = {
 	[NFTA_LOG_GROUP]	= { .type = NLA_U16 },
-	[NFTA_LOG_PREFIX]	= { .type = NLA_STRING },
+	[NFTA_LOG_PREFIX]	= { .type = NLA_STRING,
+				    .len = NF_LOG_PREFIXLEN - 1 },
 	[NFTA_LOG_SNAPLEN]	= { .type = NLA_U32 },
 	[NFTA_LOG_QTHRESHOLD]	= { .type = NLA_U16 },
 	[NFTA_LOG_LEVEL]	= { .type = NLA_U32 },