diff --git a/pkgs/desktops/cinnamon/xapp/default.nix b/pkgs/desktops/cinnamon/xapp/default.nix
index 719a8dd3968a..e09912478429 100644
--- a/pkgs/desktops/cinnamon/xapp/default.nix
+++ b/pkgs/desktops/cinnamon/xapp/default.nix
@@ -79,12 +79,11 @@ stdenv.mkDerivation rec {
     # Patch pastebin & inxi location
     sed "s|/usr/bin/pastebin|$out/bin/pastebin|" -i scripts/upload-system-info
     sed "s|'inxi'|'${inxi}/bin/inxi'|" -i scripts/upload-system-info
-
-    # Patch gtk3 module target dir
-    substituteInPlace libxapp/meson.build \
-         --replace "gtk3_dep.get_pkgconfig_variable('libdir')" "'$out'"
   '';
 
+  # Fix gtk3 module target dir. Proper upstream solution should be using define_variable.
+  PKG_CONFIG_GTK__3_0_LIBDIR = "${placeholder "out"}/lib";
+
   meta = with lib; {
     homepage = "https://github.com/linuxmint/xapp";
     description = "Cross-desktop libraries and common resources";