diff --git a/pkgs/applications/networking/instant-messengers/sflphone/default.nix b/pkgs/applications/networking/instant-messengers/sflphone/default.nix
new file mode 100644
index 00000000000..79b554798ee
--- /dev/null
+++ b/pkgs/applications/networking/instant-messengers/sflphone/default.nix
@@ -0,0 +1,79 @@
+{ stdenv, fetchurl, libyaml, alsaLib, openssl, libuuid, pkgconfig, pulseaudio, libsamplerate
+, commoncpp2, ccrtp, libzrtpcpp, dbus, dbus_cplusplus, expat, pcre, gsm, speex, ilbc, libopus
+, autoconf, automake, libtool, gettext, perl
+, cmake, qt4
+, gtk, glib, dbus_glib, libnotify, intltool }:
+
+let
+  name = "sflphone-1.2.3";
+
+  src = fetchurl {
+    url = "https://projects.savoirfairelinux.com/attachments/download/6423/${name}.tar.gz";
+    sha256 = "0aiwlky7mp5l51a7kkhkmaz7ivapypar291kdxzdxl1s3qy0x6fd";
+  };
+
+  meta = {
+    homepage = http://sflphone.org/;
+    license = "GPLv3+";
+    description = "Free software enterprise-class softphone for GNU/Linux";
+    platforms = with stdenv.lib.platforms; linux;
+    maintainers = with stdenv.lib.maintainers; [viric];
+  };
+
+in
+rec {
+  daemon = stdenv.mkDerivation {
+    name = name + "-daemon";
+
+    inherit src;
+
+    patches = [ ./libzrtpcpp-cflags.patch ];
+
+    preConfigure = ''
+      cd daemon
+
+      # Post patch, required
+      autoreconf -vfi
+
+      cd libs
+      bash ./compile_pjsip.sh
+      cd ..
+    '';
+
+    configureFlags = "--with-expat --with-expat-inc=${expat}/include " +
+      "--with-expat-lib=-lexpat --with-opus ";
+
+    buildInputs = [ libyaml alsaLib openssl libuuid pkgconfig pulseaudio libsamplerate 
+      commoncpp2 ccrtp libzrtpcpp dbus dbus_cplusplus expat pcre gsm speex ilbc libopus
+      autoconf automake libtool gettext perl ];
+  };
+
+  # This fails still.
+  # I don't know the best way to make this a KDE program (with switchable kde
+  # libs, like digikam for example)
+  /*
+  kde = stdenv.mkDerivation {
+    name = name + "-kde";
+
+    inherit src;
+
+    preConfigure = ''
+      cd kde
+    '';
+
+    buildInputs = [ daemon cmake qt4 pkgconfig ];
+  };
+  */
+
+  gnome = stdenv.mkDerivation {
+    name = name + "-gnome";
+
+    inherit src;
+
+    preConfigure = ''
+      cd gnome
+    '';
+
+    buildInputs = [ daemon pkgconfig gtk glib dbus_glib libnotify intltool ];
+  };
+}
diff --git a/pkgs/applications/networking/instant-messengers/sflphone/libzrtpcpp-cflags.patch b/pkgs/applications/networking/instant-messengers/sflphone/libzrtpcpp-cflags.patch
new file mode 100644
index 00000000000..972d9c58808
--- /dev/null
+++ b/pkgs/applications/networking/instant-messengers/sflphone/libzrtpcpp-cflags.patch
@@ -0,0 +1,15 @@
+diff --git a/daemon/src/audio/audiortp/Makefile.am b/daemon/src/audio/audiortp/Makefile.am
+index c27eedd..fe64077 100644
+--- a/daemon/src/audio/audiortp/Makefile.am
++++ b/daemon/src/audio/audiortp/Makefile.am
+@@ -4,6 +4,10 @@ noinst_LTLIBRARIES = libaudiortp.la
+ 
+ if BUILD_ZRTP
+ SFL_ZRTP_SRC=audio_zrtp_session.h audio_zrtp_session.cpp zrtp_session_callback.cpp zrtp_session_callback.h
++libaudiortp_la_CXXFLAGS = \
++		@CCGNU2_CFLAGS@ \
++		@ZRTPCPP_CFLAGS@ \
++		@CCRTP_CFLAGS@
+ endif
+ 
+ libaudiortp_la_SOURCES = \
diff --git a/pkgs/development/libraries/ccrtp/default.nix b/pkgs/development/libraries/ccrtp/default.nix
index a6e426b164a..c5ae776fe3e 100644
--- a/pkgs/development/libraries/ccrtp/default.nix
+++ b/pkgs/development/libraries/ccrtp/default.nix
@@ -8,7 +8,8 @@ stdenv.mkDerivation {
     sha256 = "1p4zzqn02zvnyjy84khiq8v65pl422fb6ni946h9sxh4yw2lgn01";
   };
 
-  buildInputs = [ openssl pkgconfig libgcrypt ucommon ];
+  buildInputs = [ openssl pkgconfig libgcrypt ];
+  propagatedBuildInputs = [ ucommon ];
 
   doCheck = true;
 
diff --git a/pkgs/development/libraries/libzrtpcpp/default.nix b/pkgs/development/libraries/libzrtpcpp/default.nix
index 9e569eea580..02741bc6fa1 100644
--- a/pkgs/development/libraries/libzrtpcpp/default.nix
+++ b/pkgs/development/libraries/libzrtpcpp/default.nix
@@ -1,4 +1,4 @@
-{ stdenv, fetchurl, cmake, ucommon, openssl, pkgconfig, ccrtp }:
+{ stdenv, fetchurl, cmake, openssl, pkgconfig, ccrtp }:
 
 stdenv.mkDerivation rec {
   name = "libzrtpcpp-2.0.0";
@@ -8,7 +8,12 @@ stdenv.mkDerivation rec {
     sha256 = "05yw8n5xpj0jxkvzgsvn3xkxirpypc1japy9k1jqs9301fgb1a3i";
   };
 
-  buildInputs = [ cmake ucommon openssl pkgconfig ccrtp ];
+  # We disallow 'lib64', or pkgconfig will not find it.
+  prePatch = ''
+    sed -i s/lib64/lib/ CMakeLists.txt
+  '';
+
+  buildInputs = [ cmake openssl pkgconfig ccrtp ];
 
   meta = { 
     description = "GNU RTP stack for the zrtp protocol developed by Phil Zimmermann";
diff --git a/pkgs/development/libraries/ucommon/default.nix b/pkgs/development/libraries/ucommon/default.nix
index cfcb47dd54f..ca0427481da 100644
--- a/pkgs/development/libraries/ucommon/default.nix
+++ b/pkgs/development/libraries/ucommon/default.nix
@@ -1,11 +1,11 @@
 { fetchurl, stdenv, gnutls, pkgconfig, zlib, libgcrypt }:
 
 stdenv.mkDerivation rec {
-  name = "ucommon-5.2.2";
+  name = "ucommon-6.0.5";
 
   src = fetchurl {
-    url = mirror://gnu/commoncpp/ucommon-5.2.2.tar.gz;
-    sha256 = "1s9r7yhvqnj57aiw7sklp2p6llfzn1jxvc3hwhpli5zq3r6kypwx";
+    url = mirror://gnu/commoncpp/ucommon-6.0.5.tar.gz;
+    sha256 = "0w5nl2a2l630n4kvfaz22by1s92ybd87g0q1zpcmsl8i5d00789l";
   };
 
   buildInputs = [ pkgconfig gnutls zlib ];
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index 058833a13a8..78d8561c2b5 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -8140,6 +8140,10 @@ let
 
   seq24 = callPackage ../applications/audio/seq24 { };
 
+  sflphone = callPackage ../applications/networking/instant-messengers/sflphone {
+    gtk = gtk3;
+  };
+
   siproxd = callPackage ../applications/networking/siproxd { };
 
   skype = callPackage_i686 ../applications/networking/instant-messengers/skype {
@@ -8148,7 +8152,6 @@ let
 
   skype4pidgin = callPackage ../applications/networking/instant-messengers/pidgin-plugins/skype4pidgin { };
 
-
   skype_call_recorder = callPackage ../applications/networking/instant-messengers/skype-call-recorder { };
 
   st = callPackage ../applications/misc/st {