diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h
index b89dcdc..f715cca 100644
--- a/net/rxrpc/ar-internal.h
+++ b/net/rxrpc/ar-internal.h
@@ -641,6 +641,7 @@
 /*
  * misc.c
  */
+extern unsigned int rxrpc_max_backlog __read_mostly;
 extern unsigned int rxrpc_requested_ack_delay;
 extern unsigned int rxrpc_soft_ack_delay;
 extern unsigned int rxrpc_idle_ack_delay;