diff --git a/CHANGELOG b/CHANGELOG
index cd4fbbe0..2af850c6 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -21,6 +21,10 @@ HISTORY
 
  ++ Bugfixes:
 
+  2011-08-22: Simon Goldschmidt
+  * tcp_out.c: fixed bug #33962 TF_FIN not always set after FIN is sent. (This
+    merely prevents nagle from not transmitting fast after closing.)
+
   2011-07-22: Simon Goldschmidt
   * api_lib.c, api_msg.c, sockets.c, api.h: fixed bug #31084 (socket API returns
     always EMSGSIZE on non-blocking sockets if data size > send buffers) -> now
diff --git a/src/core/tcp_out.c b/src/core/tcp_out.c
index a32d0258..e9ef14d8 100644
--- a/src/core/tcp_out.c
+++ b/src/core/tcp_out.c
@@ -133,6 +133,7 @@ tcp_send_fin(struct tcp_pcb *pcb)
     if ((TCPH_FLAGS(last_unsent->tcphdr) & (TCP_SYN | TCP_FIN | TCP_RST)) == 0) {
       /* no SYN/FIN/RST flag in the header, we can add the FIN flag */
       TCPH_SET_FLAG(last_unsent->tcphdr, TCP_FIN);
+      pcb->flags |= TF_FIN;
       return ERR_OK;
     }
   }