diff --git a/net/mptcp/options.c b/net/mptcp/options.c
index bd220ee4aac9..faf57585b892 100644
--- a/net/mptcp/options.c
+++ b/net/mptcp/options.c
@@ -4,6 +4,8 @@
  * Copyright (c) 2017 - 2019, Intel Corporation.
  */
 
+#define pr_fmt(fmt) "MPTCP: " fmt
+
 #include <linux/kernel.h>
 #include <net/tcp.h>
 #include <net/mptcp.h>
diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index 064639f72487..977d9c8b1453 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -3,6 +3,8 @@
  *
  * Copyright (c) 2019, Intel Corporation.
  */
+#define pr_fmt(fmt) "MPTCP: " fmt
+
 #include <linux/kernel.h>
 #include <net/tcp.h>
 #include <net/mptcp.h>
diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index a0ce7f324499..86d61ab34c7c 100644
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -4,6 +4,8 @@
  * Copyright (c) 2020, Red Hat, Inc.
  */
 
+#define pr_fmt(fmt) "MPTCP: " fmt
+
 #include <linux/inet.h>
 #include <linux/kernel.h>
 #include <net/tcp.h>