diff --git a/home/linux/gui/base/desktop-tools.nix b/home/linux/gui/base/desktop-tools.nix
index 0bc0fe5b..5a5f1c50 100644
--- a/home/linux/gui/base/desktop-tools.nix
+++ b/home/linux/gui/base/desktop-tools.nix
@@ -10,7 +10,6 @@
     # misc
     "_JAVA_AWT_WM_NONREPARENTING" = "1";
     "QT_WAYLAND_DISABLE_WINDOWDECORATION" = "1";
-    "QT_QPA_PLATFORM" = "wayland";
     "SDL_VIDEODRIVER" = "wayland";
     "GDK_BACKEND" = "wayland";
     "XDG_SESSION_TYPE" = "wayland";
diff --git a/home/linux/gui/base/noctalia/default.nix b/home/linux/gui/base/noctalia/default.nix
index cf6df0b7..8c3ab5f0 100644
--- a/home/linux/gui/base/noctalia/default.nix
+++ b/home/linux/gui/base/noctalia/default.nix
@@ -10,6 +10,13 @@ let
   package = pkgs.noctalia-shell;
 in
 {
+  # Qt for noctalia-shell (replaces former systemd user service Environment=)
+  home.sessionVariables = {
+    # Qt6: wayland primary, xcb fallback (QT_QPA_PLATFORM).
+    "QT_QPA_PLATFORM" = "wayland;xcb";
+    "QT_QPA_PLATFORMTHEME" = "qt6ct";
+    "QT_AUTO_SCREEN_SCALE_FACTOR" = "1";
+  };
 
   home.packages = [
     package
@@ -33,26 +40,4 @@ in
       "noctalia".source = mkSymlink "${confPath}/config";
       "qt6ct/qt6ct.conf".source = mkSymlink "${confPath}/qt6ct.conf";
     };
-
-  systemd.user.services.noctalia-shell = {
-    Unit = {
-      Description = "Noctalia Shell - Wayland desktop shell";
-      Documentation = "https://docs.noctalia.dev/docs";
-      PartOf = [ config.wayland.systemd.target ];
-      After = [ config.wayland.systemd.target ];
-    };
-
-    Service = {
-      ExecStart = lib.getExe package;
-      Restart = "on-failure";
-
-      Environment = [
-        "QT_QPA_PLATFORM=wayland;xcb"
-        "QT_QPA_PLATFORMTHEME=qt6ct"
-        "QT_AUTO_SCREEN_SCALE_FACTOR=1"
-      ];
-    };
-
-    Install.WantedBy = [ config.wayland.systemd.target ];
-  };
 }
diff --git a/home/linux/gui/niri/conf/config.kdl b/home/linux/gui/niri/conf/config.kdl
index 8a3fb420..f7fbeded 100644
--- a/home/linux/gui/niri/conf/config.kdl
+++ b/home/linux/gui/niri/conf/config.kdl
@@ -8,6 +8,7 @@ include "./keybindings.kdl"
 include "./windowrules.kdl"
 include "./niri-hardware.kdl"
 include "./noctalia-shell.kdl"
+include "./spawn-at-startup.kdl"
 
 spawn-sh-at-startup "bash ~/nix-config/home/linux/gui/niri/reorder-workspaces.sh"
 
diff --git a/home/linux/gui/niri/conf/spawn-at-startup.kdl b/home/linux/gui/niri/conf/spawn-at-startup.kdl
new file mode 100644
index 00000000..4cb92318
--- /dev/null
+++ b/home/linux/gui/niri/conf/spawn-at-startup.kdl
@@ -0,0 +1,3 @@
+// Noctalia: use niri spawn-at-startup (systemd user service is deprecated upstream).
+// https://docs.noctalia.dev/getting-started/compositor-settings/niri/
+spawn-at-startup "noctalia-shell"