diff --git a/lib/stringify.js b/lib/stringify.js
index bc95d2a6..f3cd99ae 100644
--- a/lib/stringify.js
+++ b/lib/stringify.js
@@ -102,11 +102,11 @@ var stringify = function stringify(
     if (isNonNullishPrimitive(obj) || utils.isBuffer(obj)) {
         if (encoder) {
             var keyValue = encodeValuesOnly ? prefix : encoder(prefix, defaults.encoder, charset, 'key', format);
-            if(generateArrayPrefix === 'comma' && encodeValuesOnly){
-                const valuesArray = String(obj).split(',');
-                let valuesJoined = '';
+            if (generateArrayPrefix === 'comma' && encodeValuesOnly) {
+                var valuesArray = String(obj).split(',');
+                var valuesJoined = '';
                 for (var i = 0; i < valuesArray.length; ++i) {
-                    valuesJoined = valuesJoined.concat(((i === 0)?'':',') + formatter(encoder(valuesArray[i], defaults.encoder, charset, 'value', format)));
+                    valuesJoined = valuesJoined.concat((i === 0 ? '' : ',') + formatter(encoder(valuesArray[i], defaults.encoder, charset, 'value', format)));
                 }
                 return [formatter(keyValue) + '=' + valuesJoined];
             }