diff --git a/sys/netinet/tcp_input.c b/sys/netinet/tcp_input.c
--- a/sys/netinet/tcp_input.c
+++ b/sys/netinet/tcp_input.c
@@ -1614,6 +1614,10 @@
 	 * XXX: This should be done after segment
 	 * validation to ignore broken/spoofed segs.
 	 */
+	if  (tp->t_idle_reduce &&
+	     (tp->snd_max == tp->snd_una) &&
+	     ((ticks - tp->t_rcvtime) >= tp->t_rxtcur))
+		cc_after_idle(tp);
 	tp->t_rcvtime = ticks;
 
 	if (thflags & TH_FIN)
diff --git a/sys/netinet/tcp_output.c b/sys/netinet/tcp_output.c
--- a/sys/netinet/tcp_output.c
+++ b/sys/netinet/tcp_output.c
@@ -155,8 +155,6 @@
 	    tcp_timer_active((tp), TT_PERSIST),				\
 	    ("neither rexmt nor persist timer is set"))
 
-static void inline	cc_after_idle(struct tcpcb *tp);
-
 #ifdef TCP_HHOOK
 /*
  * Wrapper for the TCP established output helper hook.
@@ -183,7 +181,7 @@
 /*
  * CC wrapper hook functions
  */
-static void inline
+void
 cc_after_idle(struct tcpcb *tp)
 {
 	INP_WLOCK_ASSERT(tp->t_inpcb);
diff --git a/sys/netinet/tcp_var.h b/sys/netinet/tcp_var.h
--- a/sys/netinet/tcp_var.h
+++ b/sys/netinet/tcp_var.h
@@ -1206,6 +1206,7 @@
 uint32_t tcp_hc_getmtu(struct in_conninfo *);
 void	 tcp_hc_updatemtu(struct in_conninfo *, uint32_t);
 void	 tcp_hc_update(struct in_conninfo *, struct hc_metrics_lite *);
+void 	 cc_after_idle(struct tcpcb *tp);
 
 extern	struct protosw tcp_protosw;		/* shared for TOE */
 extern	struct protosw tcp6_protosw;		/* shared for TOE */