diff --git a/pkgs/applications/video/pitivi/default.nix b/pkgs/applications/video/pitivi/default.nix
index 947d2517808..7f53aa07db6 100644
--- a/pkgs/applications/video/pitivi/default.nix
+++ b/pkgs/applications/video/pitivi/default.nix
@@ -1,7 +1,7 @@
 { stdenv, fetchurl, pkgconfig, intltool, itstool, makeWrapper
 , pythonPackages, gst, clutter-gst, clutter-gtk
 , gobjectIntrospection, clutter, gtk3, librsvg
-, gnome_icon_theme, gnome_icon_theme_symbolic
+, gnome_icon_theme, gnome_icon_theme_symbolic, gnome3
 }:
 
 let
@@ -39,20 +39,18 @@ in stdenv.mkDerivation rec {
     python pygobject3 pyxdg numpy pycairo sqlite3
   ]);
 
-  postInstall = with stdenv.lib; with gst; let
+  preFixup = with stdenv.lib; with gst; let
     libraryPath = makeLibraryPath [
       gstreamer gst-editing-services
       clutter-gst clutter-gtk clutter gtk3
-    ];
-
-    xdgDataDirs = makeSearchPath "share" [
-      gtk3 gnome_icon_theme gnome_icon_theme_symbolic
+      gnome3.gnome_desktop
     ];
   in ''
     wrapProgram "$out/bin/pitivi" \
       --set GDK_PIXBUF_MODULE_FILE "$GDK_PIXBUF_MODULE_FILE" \
       --prefix LD_LIBRARY_PATH : "${libraryPath}" \
       --prefix GST_PLUGIN_SYSTEM_PATH_1_0 : "$GST_PLUGIN_SYSTEM_PATH_1_0" \
-      --prefix XDG_DATA_DIRS : "\$XDG_ICON_DIRS:${xdgDataDirs}:$out/share"
+      --prefix XDG_DATA_DIRS : "\$XDG_ICON_DIRS:$out/share:$GSETTINGS_SCHEMAS_PATH"
+    rm $out/share/icons/hicolor/icon-theme.cache
   '';
 }