diff --git a/pkgs/development/libraries/mumlib/default.nix b/pkgs/development/libraries/mumlib/default.nix
deleted file mode 100644
index 02f0cd671f28..000000000000
--- a/pkgs/development/libraries/mumlib/default.nix
+++ /dev/null
@@ -1,28 +0,0 @@
-{ stdenv, lib, fetchFromGitHub, cmake, pkg-config
-, boost, openssl, log4cpp, libopus, protobuf }:
-with lib; stdenv.mkDerivation {
-  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 pkg-config ];
-  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
deleted file mode 100644
index c6fd2332c90c..000000000000
--- a/pkgs/servers/mumsi/default.nix
+++ /dev/null
@@ -1,27 +0,0 @@
-{ stdenv, lib, fetchFromGitHub, cmake, pkg-config, boost
-, log4cpp, pjsip, openssl, alsa-lib, mumlib }:
-with lib; stdenv.mkDerivation {
-  pname = "mumsi";
-  version = "unstable-2018-12-12";
-
-  src = fetchFromGitHub {
-    owner = "slomkowski";
-    repo = "mumsi";
-    rev = "961b75792f8da22fb5502e39edb286e32172d0b0";
-    sha256 = "0vrivl1fiiwjsz4v26nrn8ra3k9v0mcz7zjm2z319fw8hv6n1nrk";
-  };
-
-  buildInputs = [ boost log4cpp pkg-config pjsip mumlib openssl alsa-lib ];
-  nativeBuildInputs = [ cmake pkg-config ];
-  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/aliases.nix b/pkgs/top-level/aliases.nix
index a35a53b420e6..2453aa922086 100644
--- a/pkgs/top-level/aliases.nix
+++ b/pkgs/top-level/aliases.nix
@@ -575,6 +575,7 @@ mapAliases ({
   mssys = ms-sys; # added 2015-12-13
   mpv-with-scripts = self.wrapMpv self.mpv-unwrapped { }; # added 2020-05-22
   multipath_tools = multipath-tools;  # added 2016-01-21
+  mumsi = throw "mumsi has been removed from nixpkgs, as it's unmaintained and does not build anymore"; # added 2021-11-18
   mupen64plus1_5 = mupen64plus; # added 2016-02-12
   mx = throw "graalvm8 and its tools were deprecated in favor of graalvm8-ce"; # added 2021-10-15
   mxisd = throw "mxisd has been removed from nixpkgs as it has reached end of life, see https://github.com/kamax-matrix/mxisd/blob/535e0a5b96ab63cb0ddef90f6f42c5866407df95/EOL.md#end-of-life-notice . ma1sd may be a suitable alternative."; # added 2021-04-15
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index f927c1883bb3..41337a999a83 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -18678,8 +18678,6 @@ with pkgs;
 
   mueval = callPackage ../development/tools/haskell/mueval { };
 
-  mumlib = callPackage ../development/libraries/mumlib { };
-
   muparser = callPackage ../development/libraries/muparser {
     inherit (darwin.stubs) setfile;
   };
@@ -20932,8 +20930,6 @@ with pkgs;
 
   mullvad-vpn = callPackage ../applications/networking/mullvad-vpn { };
 
-  mumsi = callPackage ../servers/mumsi { };
-
   mycorrhiza = callPackage ../servers/mycorrhiza { };
 
   myserver = callPackage ../servers/http/myserver { };