diff --git a/services/ofborg/default.nix b/services/ofborg/default.nix
index 98e25c9..2136055 100644
--- a/services/ofborg/default.nix
+++ b/services/ofborg/default.nix
@@ -27,6 +27,7 @@ in {
     rabbitmq.enable = mkEnableOption "ofborg AMQP queue";
     builder.enable = mkEnableOption "ofborg builder worker";
     pastebin.enable = mkEnableOption "ofborg pastebin service";
+    mass-rebuilder.enable = mkEnableOption "ofborg evaluator worker for mass rebuilds jobs";
     stats.enable = mkEnableOption "ofborg prometheus worker";
 
     package = mkPackageOption pkgs "ofborg" { };
@@ -71,6 +72,14 @@ in {
           root = "$STATE_DIRECTORY/pastebins";
           db = "$STATE_DIRECTORY/db.json";
         };
+
+        # We use Gerrit.
+        vcs = "Gerrit";
+        gerrit = {
+          instance_uri = "cl.forkos.org";
+          ssh_private_key_file = "$CREDENTIALS_DIRECTORY/gerrit-ssh-key";
+          ssh_port = 29418;
+        };
       };
     }
     (mkIf cfg.rabbitmq.enable {
@@ -98,6 +107,9 @@ in {
     (mkIf cfg.pastebin.enable {
       systemd.services.ofborg-pastebin = mkOfborgWorker "pastebin-worker" { };
     })
+    (mkIf cfg.mass-rebuilder.enable {
+      systemd.services.ofborg-mass-rebuilder = mkOfborgWorker "mass-rebuilder" { };
+    })
     (mkIf cfg.builder.enable {
       systemd.services.ofborg-builder = mkOfborgWorker "builder" { };
     })
@@ -109,5 +121,4 @@ in {
     # systemd.services.ofborg-evaluation-filter = {};
     # systemd.services.ofborg-vcs-comment-filter = {};
     # systemd.services.ofborg-vcs-comment-poster = {};
-    # systemd.services.ofborg-mass-rebuilder = {};
 }