diff --git a/nixos/modules/services/x11/desktop-managers/mate.nix b/nixos/modules/services/x11/desktop-managers/mate.nix
index 910a246d776..f236c14fcf3 100644
--- a/nixos/modules/services/x11/desktop-managers/mate.nix
+++ b/nixos/modules/services/x11/desktop-managers/mate.nix
@@ -44,35 +44,35 @@ in
 
   config = mkIf cfg.enable {
 
-    services.xserver.desktopManager.session = singleton {
-      name = "mate";
-      bgSupport = true;
-      start = ''
-        export XDG_MENU_PREFIX=mate-
+    services.xserver.displayManager.sessionPackages = [
+      pkgs.mate.mate-session-manager
+    ];
 
-        # Let caja find extensions
-        export CAJA_EXTENSION_DIRS=$CAJA_EXTENSION_DIRS''${CAJA_EXTENSION_DIRS:+:}${config.system.path}/lib/caja/extensions-2.0
+    services.xserver.displayManager.sessionCommands = ''
+      if test "$XDG_CURRENT_DESKTOP" = "MATE"; then
+          export XDG_MENU_PREFIX=mate-
 
-        # Let caja extensions find gsettings schemas
-        ${concatMapStrings (p: ''
+          # Let caja find extensions
+          export CAJA_EXTENSION_DIRS=$CAJA_EXTENSION_DIRS''${CAJA_EXTENSION_DIRS:+:}${config.system.path}/lib/caja/extensions-2.0
+
+          # Let caja extensions find gsettings schemas
+          ${concatMapStrings (p: ''
           if [ -d "${p}/lib/caja/extensions-2.0" ]; then
-            ${addToXDGDirs p}
+              ${addToXDGDirs p}
           fi
-          '')
-          config.environment.systemPackages
-        }
+          '') config.environment.systemPackages}
 
-        # Let mate-panel find applets
-        export MATE_PANEL_APPLETS_DIR=$MATE_PANEL_APPLETS_DIR''${MATE_PANEL_APPLETS_DIR:+:}${config.system.path}/share/mate-panel/applets
-        export MATE_PANEL_EXTRA_MODULES=$MATE_PANEL_EXTRA_MODULES''${MATE_PANEL_EXTRA_MODULES:+:}${config.system.path}/lib/mate-panel/applets
+          # Add mate-control-center paths to some XDG variables because its schemas are needed by mate-settings-daemon, and mate-settings-daemon is a dependency for mate-control-center (that is, they are mutually recursive)
+          ${addToXDGDirs pkgs.mate.mate-control-center}
+      fi
+    '';
 
-        # Add mate-control-center paths to some XDG variables because its schemas are needed by mate-settings-daemon, and mate-settings-daemon is a dependency for mate-control-center (that is, they are mutually recursive)
-        ${addToXDGDirs pkgs.mate.mate-control-center}
+    # Let mate-panel find applets
+    environment.sessionVariables."MATE_PANEL_APPLETS_DIR" = "${config.system.path}/share/mate-panel/applets";
+    environment.sessionVariables."MATE_PANEL_EXTRA_MODULES" = "${config.system.path}/lib/mate-panel/applets";
 
-        ${pkgs.mate.mate-session-manager}/bin/mate-session ${optionalString cfg.debug "--debug"} &
-        waitPID=$!
-      '';
-    };
+    # Debugging
+    environment.sessionVariables.MATE_SESSION_DEBUG = mkIf cfg.debug "1";
 
     environment.systemPackages =
       pkgs.mate.basePackages ++
diff --git a/pkgs/desktops/mate/mate-session-manager/default.nix b/pkgs/desktops/mate/mate-session-manager/default.nix
index 1db0947bf2a..09973e04bc0 100644
--- a/pkgs/desktops/mate/mate-session-manager/default.nix
+++ b/pkgs/desktops/mate/mate-session-manager/default.nix
@@ -1,6 +1,6 @@
 { stdenv, fetchurl, pkgconfig, gettext, xtrans, dbus-glib, systemd,
   libSM, libXtst, gtk3, epoxy, polkit, hicolor-icon-theme, mate,
-  wrapGAppsHook
+  wrapGAppsHook, fetchpatch
 }:
 
 stdenv.mkDerivation rec {
@@ -12,6 +12,14 @@ stdenv.mkDerivation rec {
     sha256 = "01scj5d1xlri9b2id8gm9kfni9nzhdjdf7rag7fvcxwqp7baz3h3";
   };
 
+  patches = [
+    # allow turning on debugging from environment variable
+    (fetchpatch {
+      url = "https://github.com/mate-desktop/mate-session-manager/commit/3ab6fbfc811d00100d7a2959f8bbb157b536690d.patch";
+      sha256 = "0yjaklq0mp44clymyhy240kxlw95z3azmravh4f5pfm9dys33sg0";
+    })
+  ];
+
   nativeBuildInputs = [
     pkgconfig
     gettext
@@ -33,6 +41,14 @@ stdenv.mkDerivation rec {
 
   enableParallelBuilding = true;
 
+  postFixup = ''
+    substituteInPlace $out/share/xsessions/mate.desktop \
+      --replace "Exec=mate-session" "Exec=$out/bin/mate-session" \
+      --replace "TryExec=mate-session" "TryExec=$out/bin/mate-session"
+  '';
+
+  passthru.providedSessions = [ "mate" ];
+
   meta = with stdenv.lib; {
     description = "MATE Desktop session manager";
     homepage = "https://github.com/mate-desktop/mate-session-manager";