diff --git a/hosts/stonehenge/gitlab-runner.nix b/hosts/stonehenge/gitlab-runner.nix
index 580c61e..cde8cd7 100644
--- a/hosts/stonehenge/gitlab-runner.nix
+++ b/hosts/stonehenge/gitlab-runner.nix
@@ -11,7 +11,7 @@ in
   virtualisation.docker.enable = true;
   services.gitlab-runner = {
     enable = true;
-    settings.concurrent = 2;
+    settings.concurrent = 1;
     services = {
       wopus-gitlab-nix = mkNixRunnerFull {
         authenticationTokenConfigFile = config.sops.secrets."gitlab-runners/wopus-gitlab-nix".path;