diff --git a/debian/changelog b/debian/changelog
index 65815e3c5..0fc4749e9 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -2,6 +2,7 @@ grub2 (2.00-7) UNRELEASED; urgency=low
 
   * Backport from upstream:
     - Fix stderr leakage from grub-probe in is_path_readable_by_grub.
+    - Fix tftp endianness problem.
 
  -- Colin Watson <cjwatson@debian.org>  Wed, 26 Sep 2012 13:16:52 +0100
 
diff --git a/debian/patches/series b/debian/patches/series
index 27a67a786..8dc28074d 100644
--- a/debian/patches/series
+++ b/debian/patches/series
@@ -24,3 +24,4 @@ mkconfig_ubuntu_recovery.patch
 msdos_embed_off_by_one.patch
 emu_freebsd.patch
 mkconfig_stderr_handling.patch
+tftp_endianness.patch
diff --git a/debian/patches/tftp_endianness.patch b/debian/patches/tftp_endianness.patch
new file mode 100644
index 000000000..148f15fcf
--- /dev/null
+++ b/debian/patches/tftp_endianness.patch
@@ -0,0 +1,29 @@
+Description: Fix tftp endianness problem
+Author: Vladimir Serbinenko <phcoder@gmail.com>
+Origin: upstream, http://bazaar.launchpad.net/~vcs-imports/grub/grub2-bzr/revision/4548
+Forwarded: not-needed
+Applied-Upstream: http://bazaar.launchpad.net/~vcs-imports/grub/grub2-bzr/revision/4548
+Last-Update: 2012-09-26
+
+Index: b/grub-core/net/tftp.c
+===================================================================
+--- a/grub-core/net/tftp.c
++++ b/grub-core/net/tftp.c
+@@ -143,7 +143,7 @@
+ 
+   tftph_ack = (struct tftphdr *) nb_ack.data;
+   tftph_ack->opcode = grub_cpu_to_be16 (TFTP_ACK);
+-  tftph_ack->u.ack.block = block;
++  tftph_ack->u.ack.block = grub_cpu_to_be16 (block);
+ 
+   err = grub_net_send_udp_packet (data->sock, &nb_ack);
+   if (err)
+@@ -225,7 +225,7 @@
+ 	    grub_priority_queue_pop (data->pq);
+ 
+ 	    if (file->device->net->packs.count < 50)
+-	      err = ack (data, tftph->u.data.block);
++	      err = ack (data, data->block + 1);
+ 	    else
+ 	      {
+ 		file->device->net->stall = 1;
diff --git a/grub-core/net/tftp.c b/grub-core/net/tftp.c
index 9c70efbec..d0f39ea36 100644
--- a/grub-core/net/tftp.c
+++ b/grub-core/net/tftp.c
@@ -143,7 +143,7 @@ ack (tftp_data_t data, grub_uint16_t block)
 
   tftph_ack = (struct tftphdr *) nb_ack.data;
   tftph_ack->opcode = grub_cpu_to_be16 (TFTP_ACK);
-  tftph_ack->u.ack.block = block;
+  tftph_ack->u.ack.block = grub_cpu_to_be16 (block);
 
   err = grub_net_send_udp_packet (data->sock, &nb_ack);
   if (err)
@@ -225,7 +225,7 @@ tftp_receive (grub_net_udp_socket_t sock __attribute__ ((unused)),
 	    grub_priority_queue_pop (data->pq);
 
 	    if (file->device->net->packs.count < 50)
-	      err = ack (data, tftph->u.data.block);
+	      err = ack (data, data->block + 1);
 	    else
 	      {
 		file->device->net->stall = 1;