diff --git a/grunt.js b/Gruntfile.js
similarity index 60%
rename from grunt.js
rename to Gruntfile.js
index 008da40..ccdf7bd 100644
--- a/grunt.js
+++ b/Gruntfile.js
@@ -1,12 +1,14 @@
+'use strict';
+
 module.exports = function(grunt) {
 
+  // Load grunt tasks automatically
+  require('load-grunt-tasks')(grunt);
+
   // Project configuration.
   grunt.initConfig({
-    test: {
-      files: ['test/**/*.js']
-    },
-    lint: {
-      files: ['grunt.js', 'tasks/**/*.js', 'test/**/*.js']
+    nodeunit: {
+      all: ['test/**/_test.js']
     },
     watch: {
       files: '<config:lint.files>',
@@ -25,16 +27,19 @@ module.exports = function(grunt) {
         boss: true,
         eqnull: true,
         node: true,
-        es5: true
       },
-      globals: {}
+      all: [
+        'Gruntfile.js',
+        'tasks/{,*/}*.js',
+        'test/{,*/}*.js',
+      ]
     }
   });
 
-  // Load local tasks.
-  grunt.loadTasks('tasks');
-
   // Default task.
-  grunt.registerTask('default', 'lint test');
+  grunt.registerTask('default', [
+    'jshint',
+    'nodeunit:all'
+  ]);
 
 };
diff --git a/package.json b/package.json
index a677a37..925f2a0 100644
--- a/package.json
+++ b/package.json
@@ -30,10 +30,13 @@
     "test": "grunt test"
   },
   "dependencies": {
-    "grunt": "~0.3.9"
+    "grunt": "~0.4.1"
   },
   "devDependencies": {
-    "grunt": "~0.3.9"
+    "grunt": "~0.4.1",
+    "grunt-contrib-jshint": "^0.10.0",
+    "grunt-contrib-nodeunit": "^0.4.0",
+    "load-grunt-tasks": "^0.4.0"
   },
   "keywords": [
     "gruntplugin",
@@ -41,4 +44,4 @@
     "convert",
     "html"
   ]
-}
\ No newline at end of file
+}
diff --git a/tasks/wkhtmltopdf.js b/tasks/wkhtmltopdf.js
index ee673be..6f6dc05 100644
--- a/tasks/wkhtmltopdf.js
+++ b/tasks/wkhtmltopdf.js
@@ -18,33 +18,54 @@ module.exports = function(grunt) {
 
   grunt.registerMultiTask('wkhtmltopdf', 'Your task description goes here.', function() {
 
-    var htmlFiles = grunt.file.expandFiles(this.file.src),
-        dest = (this.file.dest && this.file.dest !== '') ? this.file.dest + '/' : '';
+    this.files.forEach(function(file) {
 
-    grunt.log.writeln("pdf output is: " + dest);
+      var pathlib = require('path');
+      // calculate the destination directory and ensure it exists, since
+      // wkhtmltopdf won't create the PDF if the destination directory doesn't
+      // exist
+      var destPath = file.dest;
+      if (grunt.file.isFile(file.dest)) {
+        destPath = pathlib.dirname(file.dest);
+      }
+      grunt.file.mkdir(destPath);
 
-    htmlFiles.forEach(function(srcpath) {
-      var dir = dest + srcpath.replace(/.*\/([^\/]+)\/[^\/]+\.html/, '$1');
+      file.src.forEach(function(src) {
 
-      // Create dest folder as wkhtmltopdf won't generate output if it doesn't exist
-      grunt.file.mkdir(dir);
-      var destpath  = dir + '/' +
-          srcpath.replace(/.*\/([^\/]+)\.html/, '$1.pdf');
-
-      // Launch PhantomJS.
-      helper.convert({
-        code: 90,
-        args: [
-            '--dpi', '96',        // workarround to wkhtmltopdf letter-spacing bug (see http://code.google.com/p/wkhtmltopdf/issues/detail?id=72)
-            '--print-media-type', // Use @print media type
-            srcpath,
-            destpath
-          ],
-        done: function(err) {
-          if (err) {
-            grunt.log('>>>', err);
-          }
+        var dest = file.dest;
+        // wkhtmltopdf seems to require that the destination be a file
+        // location, not a directory, so if the given destination is a
+        // directory then append the name of the source file but with the
+        // extension changed to .pdf
+        if (grunt.file.isDir(dest)) {
+          var srcFileName = pathlib.basename(src);
+          var srcFileExtension = pathlib.extname(src);
+          var destFileName = srcFileName.replace(
+            new RegExp(srcFileExtension + "$"), // match only the end of the string
+            ".pdf"
+          );
+          dest = pathlib.join(destPath + destFileName);
         }
+
+        grunt.log.writeln(
+          "Converting " + src + " -> " + dest
+        );
+
+        // Launch PhantomJS.
+        helper.convert({
+          code: 90,
+          args: [
+              '--dpi', '96',        // workarround to wkhtmltopdf letter-spacing bug (see http://code.google.com/p/wkhtmltopdf/issues/detail?id=72)
+              '--print-media-type', // Use @print media type
+              src,
+              dest
+            ],
+          done: function(err) {
+            if (err) {
+              grunt.log('>>>', err);
+            }
+          }
+        });
       });
     });
   });