diff --git a/pkgs/desktops/gnome-3/apps/gnome-boxes/default.nix b/pkgs/desktops/gnome-3/apps/gnome-boxes/default.nix
index 8921d70787c..8ce9617aaae 100644
--- a/pkgs/desktops/gnome-3/apps/gnome-boxes/default.nix
+++ b/pkgs/desktops/gnome-3/apps/gnome-boxes/default.nix
@@ -24,6 +24,9 @@ in stdenv.mkDerivation rec {
     meson ninja vala pkgconfig gettext itstool wrapGAppsHook gobjectIntrospection desktop-file-utils
   ];
 
+  # Required for USB redirection PolicyKit rules file
+  propagatedUserEnvPkgs = [ spice-gtk ];
+
   buildInputs = [
     libvirt-glib glib gtk3 gtkvnc libxml2
     libvirt spice-gtk spice-protocol libsoup json-glib webkitgtk libosinfo systemd
diff --git a/pkgs/development/libraries/spice-gtk/default.nix b/pkgs/development/libraries/spice-gtk/default.nix
index 0564459b24c..05fd952eb2e 100644
--- a/pkgs/development/libraries/spice-gtk/default.nix
+++ b/pkgs/development/libraries/spice-gtk/default.nix
@@ -52,7 +52,7 @@ in stdenv.mkDerivation rec {
 
   nativeBuildInputs = [ pkgconfig gettext libsoup autoreconfHook vala gobjectIntrospection ];
 
-  PKG_CONFIG_POLKIT_GOBJECT_1_POLICYDIR = "share/polkit-1/actions";
+  PKG_CONFIG_POLKIT_GOBJECT_1_POLICYDIR = "$(out)/share/polkit-1/actions";
 
   configureFlags = [
     "--with-gtk3"