diff --git a/pkgs/development/libraries/mumlib/default.nix b/pkgs/development/libraries/mumlib/default.nix
new file mode 100644
index 000000000000..7117599d15ec
--- /dev/null
+++ b/pkgs/development/libraries/mumlib/default.nix
@@ -0,0 +1,28 @@
+{ stdenv, lib, fetchFromGitHub, cmake, pkgconfig
+, boost, openssl, log4cpp, libopus, protobuf }:
+with lib; stdenv.mkDerivation rec {
+  pname = "mumlib";
+  version = "unstable-2018-12-12";
+
+  src = fetchFromGitHub {
+    owner = "slomkowski";
+    repo = "mumlib";
+    rev = "f91720de264c0ab5e02bb30deafc5c4b2c245eac";
+    sha256 = "0p29z8379dp2ra0420x8xjp4d3r2mf680lj38xmlc8npdzqjqjdp";
+  };
+
+  buildInputs = [ boost openssl libopus protobuf log4cpp ];
+  nativeBuildInputs = [ cmake pkgconfig ];
+  installPhase = ''
+    install -Dm555 libmumlib.so $out/lib/libmumlib.so
+    cp -a ../include $out
+  '';
+
+  meta = {
+    description = "Fairy simple Mumble library written in C++, using boost::asio asynchronous networking framework";
+    homepage = "https://github.com/slomkowski/mumlib";
+    maintainers = with maintainers; [ das_j ];
+    license = licenses.gpl2;
+    platforms = platforms.linux;
+  };
+}
diff --git a/pkgs/servers/mumsi/default.nix b/pkgs/servers/mumsi/default.nix
new file mode 100644
index 000000000000..4465febf39a9
--- /dev/null
+++ b/pkgs/servers/mumsi/default.nix
@@ -0,0 +1,27 @@
+{ stdenv, lib, fetchFromGitHub, cmake, pkgconfig, boost
+, log4cpp, pjsip, openssl, alsaLib, mumlib }:
+with lib; stdenv.mkDerivation rec {
+  pname = "mumsi";
+  version = "unstable-2018-12-12";
+
+  src = fetchFromGitHub {
+    owner = "slomkowski";
+    repo = "mumsi";
+    rev = "961b75792f8da22fb5502e39edb286e32172d0b0";
+    sha256 = "0vrivl1fiiwjsz4v26nrn8ra3k9v0mcz7zjm2z319fw8hv6n1nrk";
+  };
+
+  buildInputs = [ boost log4cpp pkgconfig pjsip mumlib openssl alsaLib ];
+  nativeBuildInputs = [ cmake pkgconfig ];
+  installPhase = ''
+    install -Dm555 mumsi $out/bin/mumsi
+  '';
+
+  meta = {
+    description = "SIP to Mumble gateway/bridge using PJSUA stack";
+    homepage = "https://github.com/slomkowski/mumsi";
+    maintainers = with maintainers; [ das_j ];
+    license = licenses.asl20;
+    platforms = platforms.linux;
+  };
+}
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index 6f79a276e164..1cb4359f604e 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -12391,6 +12391,8 @@ in
 
   mueval = callPackage ../development/tools/haskell/mueval { };
 
+  mumlib = callPackage ../development/libraries/mumlib { };
+
   muparser = callPackage ../development/libraries/muparser { };
 
   mygpoclient = pythonPackages.mygpoclient;
@@ -14411,6 +14413,8 @@ in
 
   mullvad-vpn = callPackage ../applications/networking/mullvad-vpn { };
 
+  mumsi = callPackage ../servers/mumsi { };
+
   myserver = callPackage ../servers/http/myserver { };
 
   nas = callPackage ../servers/nas { };