diff --git a/criu/sk-inet.c b/criu/sk-inet.c
index a191e78c4..1238b03dc 100644
--- a/criu/sk-inet.c
+++ b/criu/sk-inet.c
@@ -44,6 +44,11 @@
 #define PB_ALEN_INET  1
 #define PB_ALEN_INET6 4
 
+/* Definition for older kernels without MPTCP support (e.g. Ubuntu 20.04) */
+#ifndef IPPROTO_MPTCP
+#define IPPROTO_MPTCP 262
+#endif
+
 static LIST_HEAD(inet_ports);
 
 struct inet_port {