diff --git a/source/lib/workbook/builder.js b/source/lib/workbook/builder.js
index 44508eda..402b0fba 100644
--- a/source/lib/workbook/builder.js
+++ b/source/lib/workbook/builder.js
@@ -581,7 +581,7 @@ let writeToBuffer = (wb) => {
     };
 
     if (promiseObj.wb.sheets.length === 0) {
-      promiseObj.wb.Worksheet();
+      promiseObj.wb.addWorksheet();
     }
 
     addRootContentTypesXML(promiseObj)
@@ -630,4 +630,4 @@ let workbookXML = (wb) => {
 module.exports = {
   writeToBuffer,
   workbookXML
-};
\ No newline at end of file
+};