diff --git a/nixos/modules/services/mail/mailman.nix b/nixos/modules/services/mail/mailman.nix
index ded30736440e..ec2a19f58bb1 100644
--- a/nixos/modules/services/mail/mailman.nix
+++ b/nixos/modules/services/mail/mailman.nix
@@ -503,6 +503,7 @@ in {
         path = with pkgs; [ jq ];
         after = optional withPostgresql "postgresql.service";
         requires = optional withPostgresql "postgresql.service";
+        serviceConfig.RemainAfterExit = true;
         serviceConfig.Type = "oneshot";
         script = ''
           install -m0750 -o mailman -g mailman ${mailmanCfgFile} /etc/mailman.cfg