diff --git a/test/doctool/test-doctool-html.js b/test/doctool/test-doctool-html.js
index a8476b7234c9fa..8e16403901a00a 100644
--- a/test/doctool/test-doctool-html.js
+++ b/test/doctool/test-doctool-html.js
@@ -61,7 +61,14 @@ testData.forEach(function(item) {
 
   fs.readFile(item.file, 'utf8', common.mustCall(function(err, input) {
     assert.ifError(err);
-    html(input, 'foo', 'doc/template.html',
+    html(
+      {
+        input: input,
+        filename: 'foo',
+        template: 'doc/template.html',
+        nodeVersion: process.version,
+      },
+
       common.mustCall(function(err, output) {
         assert.ifError(err);
 
@@ -69,6 +76,7 @@ testData.forEach(function(item) {
         // Assert that the input stripped of all whitespace contains the
         // expected list
         assert.notEqual(actual.indexOf(expected), -1);
-      }));
+      })
+    );
   }));
 });
diff --git a/tools/doc/generate.js b/tools/doc/generate.js
index 7df987e1cf78f9..077e740432c837 100644
--- a/tools/doc/generate.js
+++ b/tools/doc/generate.js
@@ -48,11 +48,19 @@ function next(er, input) {
       break;
 
     case 'html':
-      require('./html.js')(input, inputFile, template, nodeVersion,
+      require('./html.js')(
+        {
+          input: input,
+          filename: inputFile,
+          template: template,
+          nodeVersion: nodeVersion,
+        },
+
         function(er, html) {
           if (er) throw er;
           console.log(html);
-        });
+        }
+      );
       break;
 
     default:
diff --git a/tools/doc/html.js b/tools/doc/html.js
index ef7d78d5b70ab3..de63aefa43b510 100644
--- a/tools/doc/html.js
+++ b/tools/doc/html.js
@@ -30,12 +30,12 @@ var gtocPath = path.resolve(path.join(
 var gtocLoading = null;
 var gtocData = null;
 
-function toHTML(input, filename, template, nodeVersion, cb) {
-  if (typeof nodeVersion === 'function') {
-    cb = nodeVersion;
-    nodeVersion = null;
-  }
-  nodeVersion = nodeVersion || process.version;
+/**
+ * opts: input, filename, template, nodeVersion.
+ */
+function toHTML(opts, cb) {
+  var template = opts.template;
+  var nodeVersion = opts.nodeVersion || process.version;
 
   if (gtocData) {
     return onGtocLoaded();
@@ -57,10 +57,15 @@ function toHTML(input, filename, template, nodeVersion, cb) {
   }
 
   function onGtocLoaded() {
-    var lexed = marked.lexer(input);
+    var lexed = marked.lexer(opts.input);
     fs.readFile(template, 'utf8', function(er, template) {
       if (er) return cb(er);
-      render(lexed, filename, template, nodeVersion, cb);
+      render({
+        lexed: lexed,
+        filename: opts.filename,
+        template: template,
+        nodeVersion: nodeVersion,
+      }, cb);
     });
   }
 }
@@ -87,13 +92,14 @@ function toID(filename) {
     .replace(/-+/g, '-');
 }
 
-function render(lexed, filename, template, nodeVersion, cb) {
-  if (typeof nodeVersion === 'function') {
-    cb = nodeVersion;
-    nodeVersion = null;
-  }
-
-  nodeVersion = nodeVersion || process.version;
+/**
+ * opts: lexed, filename, template, nodeVersion.
+ */
+function render(opts, cb) {
+  var lexed = opts.lexed;
+  var filename = opts.filename;
+  var template = opts.template;
+  var nodeVersion = opts.nodeVersion || process.version;
 
   // get the section
   var section = getSection(lexed);