diff --git a/lib/cartodb/api/overviews_metadata_api.js b/lib/cartodb/api/overviews_metadata_api.js
index 4e6109c1..81ab1a1c 100644
--- a/lib/cartodb/api/overviews_metadata_api.js
+++ b/lib/cartodb/api/overviews_metadata_api.js
@@ -31,18 +31,17 @@ OverviewsMetadataApi.prototype.getOverviewsMetadata = function (username, sql, c
             callback(err);
             return;
         }
-        var metadata = {};
-        rows.forEach(function(row) {
+        var metadata = rows.reduce(function(metadata, row){
             var table = row.base_table;
             var schema = row._cdb_schema_name;
             var table_metadata = metadata[table];
             if ( !table_metadata ) {
-              table_metadata = metadata[table] = {};
+                table_metadata = metadata[table] = {};
             }
             table_metadata[row.z] = { table: row.overview_table };
             table_metadata.schema = schema;
-        });
+            return metadata;
+        }, {});
         return callback(null, metadata);
     });
-
 };