diff --git a/nixos/modules/programs/dconf.nix b/nixos/modules/programs/dconf.nix
index 298abac8afa9..265c41cbbbc9 100644
--- a/nixos/modules/programs/dconf.nix
+++ b/nixos/modules/programs/dconf.nix
@@ -60,7 +60,7 @@ in
     environment.systemPackages = [ pkgs.dconf ];
 
     # Needed for unwrapped applications
-    environment.variables.GIO_EXTRA_MODULES = mkIf cfg.enable [ "${pkgs.dconf.lib}/lib/gio/modules" ];
+    environment.sessionVariables.GIO_EXTRA_MODULES = mkIf cfg.enable [ "${pkgs.dconf.lib}/lib/gio/modules" ];
   };
 
 }
diff --git a/nixos/modules/services/desktops/gnome/glib-networking.nix b/nixos/modules/services/desktops/gnome/glib-networking.nix
index 4288b6b5de61..1039605391ab 100644
--- a/nixos/modules/services/desktops/gnome/glib-networking.nix
+++ b/nixos/modules/services/desktops/gnome/glib-networking.nix
@@ -38,7 +38,7 @@ with lib;
 
     systemd.packages = [ pkgs.glib-networking ];
 
-    environment.variables.GIO_EXTRA_MODULES = [ "${pkgs.glib-networking.out}/lib/gio/modules" ];
+    environment.sessionVariables.GIO_EXTRA_MODULES = [ "${pkgs.glib-networking.out}/lib/gio/modules" ];
 
   };
 
diff --git a/nixos/modules/services/desktops/gvfs.nix b/nixos/modules/services/desktops/gvfs.nix
index 27864fad4f26..1aa64ea37db5 100644
--- a/nixos/modules/services/desktops/gvfs.nix
+++ b/nixos/modules/services/desktops/gvfs.nix
@@ -57,7 +57,7 @@ in
     services.udev.packages = [ pkgs.libmtp.out ];
 
     # Needed for unwrapped applications
-    environment.variables.GIO_EXTRA_MODULES = [ "${cfg.package}/lib/gio/modules" ];
+    environment.sessionVariables.GIO_EXTRA_MODULES = [ "${cfg.package}/lib/gio/modules" ];
 
   };
 
diff --git a/nixos/modules/services/x11/display-managers/gdm.nix b/nixos/modules/services/x11/display-managers/gdm.nix
index f9d4d3d68364..b1dc6643be82 100644
--- a/nixos/modules/services/x11/display-managers/gdm.nix
+++ b/nixos/modules/services/x11/display-managers/gdm.nix
@@ -140,7 +140,8 @@ in
         environment = {
           GDM_X_SERVER_EXTRA_ARGS = toString
             (filter (arg: arg != "-terminate") cfg.xserverArgs);
-          XDG_DATA_DIRS = "${cfg.sessionData.desktops}/share/";
+          # GDM is needed for gnome-login.session
+          XDG_DATA_DIRS = "${gdm}/share:${cfg.sessionData.desktops}/share";
         } // optionalAttrs (xSessionWrapper != null) {
           # Make GDM use this wrapper before running the session, which runs the
           # configured setupCommands. This relies on a patched GDM which supports
diff --git a/nixos/modules/testing/test-instrumentation.nix b/nixos/modules/testing/test-instrumentation.nix
index a7011be7e042..01447e6ada87 100644
--- a/nixos/modules/testing/test-instrumentation.nix
+++ b/nixos/modules/testing/test-instrumentation.nix
@@ -109,6 +109,10 @@ in
       # Allow very slow start
       DefaultTimeoutStartSec=300
     '';
+    systemd.user.extraConfig = ''
+      # Allow very slow start
+      DefaultTimeoutStartSec=300
+    '';
 
     boot.consoleLogLevel = 7;