diff --git a/flake.nix b/flake.nix
index fe41995..6430faa 100644
--- a/flake.nix
+++ b/flake.nix
@@ -32,7 +32,7 @@
               # pkgs.python310Packages.pygobject3
               # pkgs.cairo
               # pkgs.gobject-introspection
-              # pkgs.gtk4
+              pkgs.gtk4
               # pkgs.pkg-config
             ];
           };
diff --git a/gnome_random_background/main.py b/gnome_random_background/main.py
index 54e38e5..3ebcdc0 100644
--- a/gnome_random_background/main.py
+++ b/gnome_random_background/main.py
@@ -3,7 +3,7 @@ import random
 
 import gi
 
-gi.require_version("Gtk", "3.0")
+gi.require_version("Gtk", "4.0")
 from gi.repository import Gio, Gtk
 
 import click