diff --git a/nixos/tests/gnome3-xorg.nix b/nixos/tests/gnome3-xorg.nix
index 61fcc9302832..0d05c12384f3 100644
--- a/nixos/tests/gnome3-xorg.nix
+++ b/nixos/tests/gnome3-xorg.nix
@@ -14,6 +14,7 @@ import ./make-test-python.nix ({ pkgs, lib, ...} : {
 
       services.xserver.displayManager = {
         gdm.enable = true;
+        gdm.debug = true;
         autoLogin = {
           enable = true;
           user = user.name;
@@ -21,6 +22,7 @@ import ./make-test-python.nix ({ pkgs, lib, ...} : {
       };
 
       services.xserver.desktopManager.gnome3.enable = true;
+      services.xserver.desktopManager.gnome3.debug = true;
       services.xserver.displayManager.defaultSession = "gnome-xorg";
 
       virtualisation.memorySize = 1024;
diff --git a/nixos/tests/gnome3.nix b/nixos/tests/gnome3.nix
index 509792515ce3..b3d7aff8bd71 100644
--- a/nixos/tests/gnome3.nix
+++ b/nixos/tests/gnome3.nix
@@ -13,6 +13,7 @@ import ./make-test-python.nix ({ pkgs, lib, ...} : {
 
       services.xserver.displayManager = {
         gdm.enable = true;
+        gdm.debug = true;
         autoLogin = {
           enable = true;
           user = "alice";
@@ -20,6 +21,7 @@ import ./make-test-python.nix ({ pkgs, lib, ...} : {
       };
 
       services.xserver.desktopManager.gnome3.enable = true;
+      services.xserver.desktopManager.gnome3.debug = true;
 
       virtualisation.memorySize = 1024;
     };