diff --git a/README.md b/README.md
index db5c23f..c9020e9 100644
--- a/README.md
+++ b/README.md
@@ -41,7 +41,7 @@ pdf.create(html, options).toFile('./businesscard.pdf', function(err, res) {
 
 ```js
 var pdf = require('html-pdf');
-pdf.create(html).toFile([filepath, ]function(err, res){
+pdf.create(html).toFile([filepath, ], function(err, res){
   console.log(res.filename);
 });
 
diff --git a/lib/pdf.js b/lib/pdf.js
index afb8791..af5cac5 100644
--- a/lib/pdf.js
+++ b/lib/pdf.js
@@ -75,7 +75,7 @@ PDF.prototype.toStream = function PdfToStream (callback) {
 }
 
 PDF.prototype.toFile = function PdfToFile (filename, callback) {
-  assert(arguments.length > 0, 'html-pdf: The method .toFile([filename, ]callback) requires a callback.')
+  assert(arguments.length > 0, 'html-pdf: The method .toFile([filename, ], callback) requires a callback.')
   if (filename instanceof Function) {
     callback = filename
     filename = undefined