diff --git a/l2tpns.c b/l2tpns.c
index 9a8fd4d..df9e4c8 100644
--- a/l2tpns.c
+++ b/l2tpns.c
@@ -1391,6 +1391,9 @@ static void set_kernel_accel(sessionidt s, int set, int now)
 
 	if (set)
 	{
+		if (t == T_FREE)
+			/* This is a session that got freed */
+			return;
 		if (tunnel[t].state == TUNNELUNDEF)
 			/* We don't know the tunnel yet */
 			return;