diff --git a/pkgs/desktops/mate/mate-session-manager/default.nix b/pkgs/desktops/mate/mate-session-manager/default.nix
index 04eb487adba9..09973e04bc0a 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