diff --git a/lib/cartodb/backends/cluster.js b/lib/cartodb/backends/cluster.js
index 31a2c7e9..8ad2343c 100644
--- a/lib/cartodb/backends/cluster.js
+++ b/lib/cartodb/backends/cluster.js
@@ -7,7 +7,7 @@ const AggregationMapConfig = require('../models/aggregation/aggregation-mapconfi
 
 module.exports = class ClusterBackend {
     // TODO: reduce complexity
-    // jshint maxcomplexity: 16
+    // jshint maxcomplexity: 15
     getClusterFeatures (mapConfigProvider, params, callback) {
         mapConfigProvider.getMapConfig((err, _mapConfig) => {
             if (err) {
@@ -61,7 +61,7 @@ module.exports = class ClusterBackend {
 
                 const { columns, expressions } = aggregation;
 
-                if (!Array.isArray(columns) || !columns.length) {
+                if (!hasColumns(columns)) {
                     const error = new Error(
                         `Invalid aggregation input, columns should be and array of column names`
                     );
@@ -261,3 +261,7 @@ function hasAggregationLayer (mapConfig, layerIndex) {
 
     return mapConfig.isAggregationLayer(layerIndex);
 }
+
+function hasColumns (columns) {
+    return Array.isArray(columns) && columns.length;
+}