diff --git a/pkgs/applications/networking/instant-messengers/telegram/tdesktop/default.nix b/pkgs/applications/networking/instant-messengers/telegram/tdesktop/default.nix
index f4ade0767261..05dbfbdaf968 100644
--- a/pkgs/applications/networking/instant-messengers/telegram/tdesktop/default.nix
+++ b/pkgs/applications/networking/instant-messengers/telegram/tdesktop/default.nix
@@ -1,7 +1,8 @@
 { mkDerivation, lib, fetchurl, fetchsvn
 , pkgconfig, cmake, ninja, python3, wrapGAppsHook, wrapQtAppsHook
-, qtbase, qtimageformats, gtk3, libappindicator-gtk3, enchant2, lz4, xxHash
+, qtbase, qtimageformats, gtk3, libsForQt5, enchant2, lz4, xxHash
 , dee, ffmpeg_4, openalSoft, minizip, libopus, alsaLib, libpulseaudio, range-v3
+, tl-expected, microsoft_gsl
 # TODO: Shouldn't be required:
 , pcre, xorg, utillinux, libselinux, libsepol, epoxy, at-spi2-core, libXtst
 , xdg_utils
@@ -18,17 +19,15 @@ with lib;
 
 mkDerivation rec {
   pname = "telegram-desktop";
-  version = "1.9.9";
+  version = "1.9.12";
 
   # Telegram-Desktop with submodules
   src = fetchurl {
     url = "https://github.com/telegramdesktop/tdesktop/releases/download/v${version}/tdesktop-${version}-full.tar.gz";
-    sha256 = "08bxlqiapj9yqj9ywni33n5k7n3ckgfhv200snjqyqy9waqph1i6";
+    sha256 = "1xjf2fh6qry4q6frq2ixmn1k0rsc72h4j0zmahfsggyl3j5mgkx1";
   };
 
   postPatch = ''
-    substituteInPlace Telegram/SourceFiles/platform/linux/linux_libs.cpp \
-      --replace '"appindicator3"' '"${libappindicator-gtk3}/lib/libappindicator3.so"'
     substituteInPlace Telegram/lib_spellcheck/spellcheck/platform/linux/linux_enchant.cpp \
       --replace '"libenchant-2.so.2"' '"${enchant2}/lib/libenchant-2.so.2"'
     substituteInPlace Telegram/CMakeLists.txt \
@@ -42,8 +41,9 @@ mkDerivation rec {
   nativeBuildInputs = [ pkgconfig cmake ninja python3 wrapGAppsHook wrapQtAppsHook ];
 
   buildInputs = [
-    qtbase qtimageformats gtk3 libappindicator-gtk3 enchant2 lz4 xxHash
+    qtbase qtimageformats gtk3 libsForQt5.libdbusmenu enchant2 lz4 xxHash
     dee ffmpeg_4 openalSoft minizip libopus alsaLib libpulseaudio range-v3
+    tl-expected microsoft_gsl
     # TODO: Shouldn't be required:
     pcre xorg.libpthreadstubs xorg.libXdmcp utillinux libselinux libsepol epoxy at-spi2-core libXtst
   ];
@@ -58,6 +58,7 @@ mkDerivation rec {
     "-DDESKTOP_APP_USE_GLIBC_WRAPS=OFF"
     "-DDESKTOP_APP_USE_PACKAGED=ON"
     "-DDESKTOP_APP_USE_PACKAGED_RLOTTIE=OFF"
+    "-DDESKTOP_APP_USE_PACKAGED_VARIANT=OFF"
     "-DDESKTOP_APP_DISABLE_CRASH_REPORTS=ON"
     "-DTDESKTOP_DISABLE_REGISTER_CUSTOM_SCHEME=ON"
     "-DTDESKTOP_DISABLE_DESKTOP_FILE_GENERATION=ON"
@@ -80,6 +81,7 @@ mkDerivation rec {
   #   - upstream: https://github.com/grishka/libtgvoip
   # Both of these packages are included in this PR (kotatogram-desktop):
   # https://github.com/NixOS/nixpkgs/pull/75210
+  # TODO: Package mapbox-variant
 
   postFixup = ''
     # This is necessary to run Telegram in a pure environment.
diff --git a/pkgs/development/libraries/tl-expected/default.nix b/pkgs/development/libraries/tl-expected/default.nix
new file mode 100644
index 000000000000..9de97229e0b6
--- /dev/null
+++ b/pkgs/development/libraries/tl-expected/default.nix
@@ -0,0 +1,24 @@
+{ stdenv, fetchFromGitHub, cmake }:
+
+stdenv.mkDerivation rec {
+  pname = "tl-expected-unstable";
+  version = "2019-11-11"; # 5 commits ahead of version 1.0.0
+
+  src = fetchFromGitHub {
+    owner = "TartanLlama";
+    repo = "expected";
+    rev = "1d9c5d8c0da84b8ddc54bd3d90d632eec95c1f13";
+    fetchSubmodules = true;
+    sha256 = "0rzfn9yyg70zwpxbmv22qy0015baymi2rdd65ixmcb31fgnap68i";
+  };
+
+  nativeBuildInputs = [ cmake ];
+
+  meta = with stdenv.lib; {
+    description = "C++11/14/17 std::expected with functional-style extensions";
+    homepage = https://tl.tartanllama.xyz/en/latest/api/expected.html;
+    license = licenses.cc0;
+    platforms = platforms.all;
+    maintainers = with maintainers; [ primeos ];
+  };
+}
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index 88ce26c91e85..7feffda07ccb 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -14456,6 +14456,8 @@ in
   tk-8_6 = callPackage ../development/libraries/tk/8.6.nix { };
   tk-8_5 = callPackage ../development/libraries/tk/8.5.nix { tcl = tcl-8_5; };
 
+  tl-expected = callPackage ../development/libraries/tl-expected { };
+
   tnt = callPackage ../development/libraries/tnt { };
 
   tntnet = callPackage ../development/libraries/tntnet { };