diff --git a/nixos/modules/services/monitoring/thanos.nix b/nixos/modules/services/monitoring/thanos.nix
index 5baa0d8446e5..02502816ef5d 100644
--- a/nixos/modules/services/monitoring/thanos.nix
+++ b/nixos/modules/services/monitoring/thanos.nix
@@ -394,9 +394,8 @@ let
         Maximum number of queries processed concurrently by query node.
       '';
 
-      query.replica-labels = mkAttrsParam "query.replica-label" ''
+      query.replica-labels = mkListParam "query.replica-label" ''
         Labels to treat as a replica indicator along which data is
-
         deduplicated.
 
         Still you will be able to query without deduplication using