diff --git a/synapse-module/default.nix b/synapse-module/default.nix
index 4652c87..b2b09f2 100644
--- a/synapse-module/default.nix
+++ b/synapse-module/default.nix
@@ -614,7 +614,7 @@ in
             port = wRP;
           }
         );
-        services.matrix-synapse-next.settings.stream_writers.events = lib.optional (cfg.workers.eventPersisters > 0) (lib.genList (i: "auto-event-persist${toString (i + 1)}") cfg.workers.eventPersisters); 
+        services.matrix-synapse-next.settings.stream_writers.events = lib.mkIf (cfg.workers.eventPersisters > 0) (lib.genList (i: "auto-event-persist${toString (i + 1)}") cfg.workers.eventPersisters); 
         services.matrix-synapse-next.workers.instances = genAttrs' (lib.lists.range 1 cfg.workers.eventPersisters)
           (i: "auto-event-persist${toString i}")
           (i: {