diff --git a/nixos/tests/gnome3.nix b/nixos/tests/gnome3.nix
index df30283e3155..6f2925e52fa4 100644
--- a/nixos/tests/gnome3.nix
+++ b/nixos/tests/gnome3.nix
@@ -11,6 +11,8 @@ import ./make-test.nix {
       services.xserver.displayManager.auto.enable = true;
       services.xserver.displayManager.auto.user = "alice";
       services.xserver.desktopManager.gnome3.enable = true;
+
+      virtualisation.memorySize = 512;
     };
 
   testScript =
diff --git a/nixos/tests/gnome3_12.nix b/nixos/tests/gnome3_12.nix
index 723d1bc45229..3b38d779b6f8 100644
--- a/nixos/tests/gnome3_12.nix
+++ b/nixos/tests/gnome3_12.nix
@@ -12,6 +12,8 @@ import ./make-test.nix {
       services.xserver.displayManager.auto.user = "alice";
       services.xserver.desktopManager.gnome3.enable = true;
       environment.gnome3.packageSet = pkgs.gnome3_12;
+
+      virtualisation.memorySize = 512;
     };
 
   testScript =