diff --git a/dhcp-stateless-DUID-LLT.patch b/dhcp-stateless-DUID-LLT.patch
new file mode 100644
index 0000000..a7f22b5
--- /dev/null
+++ b/dhcp-stateless-DUID-LLT.patch
@@ -0,0 +1,48 @@
+From 61fa3dd9e789997f66e848c7e3fb2f554ee374e2 Mon Sep 17 00:00:00 2001
+From: Jiri Popelka <jpopelka@redhat.com>
+Date: Thu, 18 Dec 2014 11:53:26 +0100
+Subject: [PATCH] Write DUID_LLT even in stateless mode.
+
+By default, DHCPv6 dhclient creates DUID-LL
+if it is running in stateless mode (-6 -S) and
+doesn't write it into leases file, most likely
+because the DUID-LL is always generated the same.
+
+It's however possible to specify DUID to be of type LLT instead of LL
+with '-D LLT'. Rfc 3315 says that:
+'Clients and servers using this type of DUID MUST
+store the DUID-LLT in stable storage.'
+That's not fulfiled in this case (-6 -S -D LLT),
+because it's generated each time again.
+
+It's not a big deal because the server doesn't store any
+info about 'stateless' clients, so it doesn't matter
+that the DUID-LLT is different each time.
+But there's a TAHI test which tests this, i.e. that
+DUID-LLT is still the same even in stateless mode.
+It's a test DHCP_CONF.7.1.9, part B.
+https://www.ipv6ready.org/docs/Phase2_DHCPv6_Conformance_Latest.pdf
+
+Signed-off-by: Jiri Popelka <jpopelka@redhat.com>
+---
+ client/dhclient.c | 4 +++-
+ 1 file changed, 3 insertions(+), 1 deletion(-)
+
+diff --git a/client/dhclient.c b/client/dhclient.c
+index 5ef59cd..026e3fe 100644
+--- a/client/dhclient.c
++++ b/client/dhclient.c
+@@ -788,7 +788,9 @@ void run_stateless(int exit_mode)
+ 		if (default_duid.buffer != NULL)
+ 			data_string_forget(&default_duid, MDL);
+ 
+-		form_duid(&default_duid, MDL);
++		if (form_duid(&default_duid, MDL) == ISC_R_SUCCESS &&
++		    duid_type == DUID_LLT)
++			write_duid(&default_duid);
+ 	}
+ 
+ 	/* Start a configuration state machine. */
+-- 
+2.1.0
+
diff --git a/dhcp.spec b/dhcp.spec
index a5bb68c..b010c98 100644
--- a/dhcp.spec
+++ b/dhcp.spec
@@ -18,7 +18,7 @@
 Summary:  Dynamic host configuration protocol software
 Name:     dhcp
 Version:  4.3.1
-Release:  17%{?dist}
+Release:  18%{?dist}
 # NEVER CHANGE THE EPOCH on this package.  The previous maintainer (prior to
 # dcantrell maintaining the package) made incorrect use of the epoch and
 # that's why it is at 12 now.  It should have never been used, but it was.
@@ -78,6 +78,7 @@ Patch38:  dhcp-skip-vlan.patch
 Patch39:  dhcp-relay-hop-limit.patch
 Patch40:  dhcp-ldapgssapi.patch
 Patch41:  dhcp-option97-pxe-client-id.patch
+Patch42:  dhcp-stateless-DUID-LLT.patch
 Patch100: dhcp-bind996.patch
 
 BuildRequires: autoconf
@@ -377,6 +378,10 @@ rm -rf includes/isc-dhcp
 # (Submitted to dhcp-bugs@isc.org - [ISC-Bugs #38110])
 %patch41 -p1 -b .option97
 
+# dhclient: write DUID_LLT even in stateless mode (#1156356)
+# (Submitted to dhcp-bugs@isc.org - [ISC-Bugs #38144])
+%patch42 -p1 -b .stateless-DUID-LLT
+
 # to build against bind-9.9.6
 %patch100 -p1 -b .bind996
 
@@ -680,6 +685,9 @@ done
 %doc doc/html/
 
 %changelog
+* Thu Dec 18 2014 Jiri Popelka <jpopelka@redhat.com> - 12:4.3.1-18
+- dhclient: write DUID_LLT even in stateless mode (#1156356)
+
 * Wed Dec 17 2014 Jiri Popelka <jpopelka@redhat.com> - 12:4.3.1-17
 - option 97 - pxe-client-id (#1058674)