diff --git a/nixos/modules/services/networking/prosody.nix b/nixos/modules/services/networking/prosody.nix
index 1cb047c9b125..d1de1854c938 100644
--- a/nixos/modules/services/networking/prosody.nix
+++ b/nixos/modules/services/networking/prosody.nix
@@ -567,7 +567,7 @@ let
 
       ${lib.concatMapStrings (muc: ''
         Component ${toLua muc.domain} "muc"
-            modules_enabled = {${optionalString cfg.modules.mam ''" muc_mam";''}${optionalString muc.allowners_muc ''" muc_allowners";''} }
+            modules_enabled = {${optionalString cfg.modules.mam ''" muc_mam",''}${optionalString muc.allowners_muc ''" muc_allowners",''} }
             name = ${toLua muc.name}
             restrict_room_creation = ${toLua muc.restrictRoomCreation}
             max_history_messages = ${toLua muc.maxHistoryMessages}