diff --git a/lib/json2csv.js b/lib/json2csv.js
index 106fdc2f..1406eb27 100644
--- a/lib/json2csv.js
+++ b/lib/json2csv.js
@@ -87,7 +87,9 @@ function checkParams(params) {
   }
 
   if (params.flatten) {
-    params.data = params.data.map(flatten);
+    params.data = params.data.map(function (data) {
+      return flatten(data, { useToJSON: true });
+    });
   }
 
   // Set params.fields default to first data element's keys