diff --git a/nixos/modules/services/amqp/rabbitmq.nix b/nixos/modules/services/amqp/rabbitmq.nix
index 7dce9d242916..0105f2e31333 100644
--- a/nixos/modules/services/amqp/rabbitmq.nix
+++ b/nixos/modules/services/amqp/rabbitmq.nix
@@ -210,8 +210,7 @@ in
 
       preStart = ''
         ${optionalString (cfg.cookie != "") ''
-            echo -n ${cfg.cookie} > ${cfg.dataDir}/.erlang.cookie
-            chmod 600 ${cfg.dataDir}/.erlang.cookie
+          install -m 600 <(echo -n ${cfg.cookie}) ${cfg.dataDir}/.erlang.cookie
         ''}
       '';
     };