diff --git a/nixos/modules/services/x11/desktop-managers/pantheon.nix b/nixos/modules/services/x11/desktop-managers/pantheon.nix
index 25ef1cbfc67e..99db5b17b649 100644
--- a/nixos/modules/services/x11/desktop-managers/pantheon.nix
+++ b/nixos/modules/services/x11/desktop-managers/pantheon.nix
@@ -163,7 +163,7 @@ in
 
     # Settings from elementary-default-settings
     environment.sessionVariables.GTK_CSD = "1";
-    environment.sessionVariables.GTK_MODULES = "pantheon-filechooser-module";
+    environment.sessionVariables.GTK3_MODULES = [ "pantheon-filechooser-module" ];
     environment.etc."gtk-3.0/settings.ini".source = "${pkgs.pantheon.elementary-default-settings}/etc/gtk-3.0/settings.ini";
 
     environment.pathsToLink = [