diff --git a/src/vnet/session/session_node.c b/src/vnet/session/session_node.c
index 6ef461a..3413172 100644
--- a/src/vnet/session/session_node.c
+++ b/src/vnet/session/session_node.c
@@ -570,7 +570,8 @@
   ctx->tc = session_tx_get_transport (ctx, peek_data);
   ctx->snd_mss = ctx->transport_vft->send_mss (ctx->tc);
   ctx->snd_space =
-    transport_connection_max_tx_burst (ctx->tc, vm->clib_time.last_cpu_time);
+    transport_connection_snd_space (ctx->tc, vm->clib_time.last_cpu_time,
+				    ctx->snd_mss);
   if (ctx->snd_space == 0 || ctx->snd_mss == 0)
     {
       vec_add1 (wrk->pending_event_vector, *e);