diff --git a/include/net/ip.h b/include/net/ip.h
index b659a837ccd7..7f5ba12834b0 100644
--- a/include/net/ip.h
+++ b/include/net/ip.h
@@ -284,7 +284,7 @@ void ipfrag_init(void);
 void ip_static_sysctl_init(void);
 
 #define IP4_REPLY_MARK(net, mark) \
-	((net)->ipv4.sysctl_fwmark_reflect ? (mark) : 0)
+	(READ_ONCE((net)->ipv4.sysctl_fwmark_reflect) ? (mark) : 0)
 
 static inline bool ip_is_fragment(const struct iphdr *iph)
 {