diff --git a/CHANGELOG b/CHANGELOG
index 5c215f4a..2be6573c 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -32,6 +32,10 @@ HISTORY
 
  ++ Bugfixes:
 
+  2011-09-11: Simon Goldschmidt
+  * tcp_out.c: use pcb->mss instead of TCP_MSS for preallocate mss-sized pbufs
+    (bug #34019)
+
   2011-09-09: Simon Goldschmidt
   * udp.c: fixed bug #34072: UDP broadcast is received from wrong UDP pcb if
     udp port matches
diff --git a/src/core/tcp_out.c b/src/core/tcp_out.c
index e9ef14d8..d0ff42a4 100644
--- a/src/core/tcp_out.c
+++ b/src/core/tcp_out.c
@@ -229,7 +229,7 @@ tcp_pbuf_prealloc(pbuf_layer layer, u16_t length, u16_t max_length,
   LWIP_UNUSED_ARG(apiflags);
   LWIP_UNUSED_ARG(first_seg);
   /* always create MSS-sized pbufs */
-  alloc = TCP_MSS;
+  alloc = pcb->mss;
 #else /* LWIP_NETIF_TX_SINGLE_PBUF */
   if (length < max_length) {
     /* Should we allocate an oversized pbuf, or just the minimum