diff --git a/nixos/utils.nix b/nixos/utils.nix
index cec705c1..caba604d 100644
--- a/nixos/utils.nix
+++ b/nixos/utils.nix
@@ -124,8 +124,10 @@ in {
           "gtk"
           "hyprland"
         ];
-        # Pick files / choose download paths with yazi instead of the GTK dialog
-        "org.freedesktop.portal.FileChooser" = ["termfilechooser"];
+        # Pick files / choose download paths with yazi instead of the GTK dialog.
+        # Key MUST use the "impl" interface name, else xdg-desktop-portal
+        # ignores it and falls back to the default (gtk). See portals.conf(5).
+        "org.freedesktop.impl.portal.FileChooser" = ["termfilechooser"];
       };
     };