diff --git a/lib/cartodb/models/mapconfig/adapter/mapconfig-overviews-adapter.js b/lib/cartodb/models/mapconfig/adapter/mapconfig-overviews-adapter.js
index 9a5a1417..240ace22 100644
--- a/lib/cartodb/models/mapconfig/adapter/mapconfig-overviews-adapter.js
+++ b/lib/cartodb/models/mapconfig/adapter/mapconfig-overviews-adapter.js
@@ -75,7 +75,6 @@ function augmentLayer(overviewsMetadataBackend, filterStatsBackend, user, layer,
         var filters = queryRewriteData.filters;
 
         if (!filters) {
-            layer = Object.assign({}, layer);
             layer.options = Object.assign({}, layer.options, { query_rewrite_data: queryRewriteData });
 
             return callback(null, layer);
@@ -90,7 +89,6 @@ function augmentLayer(overviewsMetadataBackend, filterStatsBackend, user, layer,
 
             queryRewriteData.filter_stats = stats;
 
-            layer = Object.assign({}, layer);
             layer.options = Object.assign({}, layer.options, { query_rewrite_data: queryRewriteData });
 
             return callback(null, layer);