diff --git a/nixos/tests/gitlab.nix b/nixos/tests/gitlab.nix
index 3e9feeb0769d..dc3b889c8e8e 100644
--- a/nixos/tests/gitlab.nix
+++ b/nixos/tests/gitlab.nix
@@ -14,6 +14,8 @@ import ./make-test-python.nix ({ pkgs, lib, ...} : with lib; {
       imports = [ common/user-account.nix ];
 
       virtualisation.memorySize = if pkgs.stdenv.is64bit then 4096 else 2047;
+      virtualisation.cores = 4;
+      virtualisation.useNixStoreImage = true;
       systemd.services.gitlab.serviceConfig.Restart = mkForce "no";
       systemd.services.gitlab-workhorse.serviceConfig.Restart = mkForce "no";
       systemd.services.gitaly.serviceConfig.Restart = mkForce "no";