diff --git a/README.md b/README.md
index d697ee6..16e52f9 100644
--- a/README.md
+++ b/README.md
@@ -51,7 +51,7 @@ Grunt configuration
 
 Grunt-Dock supports main and targets level configuration.
 
-Here is basic Grunt configuration:
+Here is a basic Grunt configuration:
 
 ```javascript
 dock: {
@@ -106,7 +106,11 @@ dock: {
 } // dock
 ```
 
-The property 'dockerfile' can be any supported Docker formats plus plain format (this case, Grunt-Dock will create a tar.gz stream to pass to Docker - very usefull for development -). 
+The property 'dockerfile' supports:
+
+ * **tar archive** any tarballs supported by Docker (.tar, .tar.gz, .tar.bz2, .tar.xz). It will be passed directly to the Docker server.
+ * **directory** Grunt-Dock will create a tarball (gz compressed) of this directory before sending it to Docker.
+ * **plain file** Grunt-Dock will create a tarball containing 1 "Dockerfile" file.
 
 You can define some specifics options to pass for each commands of each images (start, stop, build, etc.).
 See Docker API/Dockerode documentations.
diff --git a/lib/build.js b/lib/build.js
index 286cad8..02dd34a 100644
--- a/lib/build.js
+++ b/lib/build.js
@@ -6,6 +6,7 @@
 var fs = require('fs'),
     path = require('path'),
     tar = require('tar-stream'),
+    tarfs = require('tar-fs'),
     concat = require('concat-stream'),
     zlib = require('zlib'),
     async = require('async'),
@@ -56,26 +57,55 @@ var buildCommands = function(grunt, docker, options, done, tag) {
   // Tar + gz if plain content.
   var process = function(tag, image, callback) {
 
+    if (!image.dockerfile) return callback(new Error('Dockerfile is null.'));
+
     // Create the options object for the build
     var imageOptions = image.options || {};
     var buildOpts = utils.merge({t: tag}, imageOptions.build || {});
 
-    var fileExt = path.extname(image.dockerfile);
+    var stats = fs.statSync(path.resolve(image.dockerfile));
 
-    if (fileExt) {
+    // Option 1: source is directory, pack it
+    if (stats.isDirectory()) {
+      tarfs.pack(path.resolve(image.dockerfile))
+        .pipe(zlib.createGzip())
+        .pipe(concat(function (data) {
+          build(data, buildOpts, callback);
+        }));
+    }
+    else if (stats.isFile()) {
       var content;
-
       try {
         content = fs.readFileSync(image.dockerfile);
-      } catch (e) {
+      } catch(e) {
         return done(e);
       }
 
-      build(content, buildOpts, callback);
-    } else {
-      tarfs.pack(path.dirname(path.resolve(image.dockerfile))).pipe(zlib.createGzip()).pipe(concat(function (data) {
-        build(data, buildOpts, callback);
-      }));
+      var isTar = utils.isTarFile(image.dockerfile);
+
+      switch(isTar) {
+        case true:
+          // The file is already a tar, build with it.
+          build(content, buildOpts, callback);
+          break;
+
+        case false:
+          // Compress the file before sending to docker
+          var pack = tar.pack();
+          pack.entry({ name:'Dockerfile' }, content);
+          pack.finalize();
+
+          pack.pipe(zlib.createGzip())
+            .pipe(concat(function(data) {
+              build(data, buildOpts, callback);
+            }));
+
+          break;
+      }
+
+    }
+    else {
+      return callback(new Error('Unsupported format.'));
     }
   };
 
diff --git a/lib/utils.js b/lib/utils.js
index 328d4d7..cfec53c 100644
--- a/lib/utils.js
+++ b/lib/utils.js
@@ -97,5 +97,23 @@ utils.getUserHome = function() {
   return process.env.HOME || process.env.HOMEPATH || process.env.USERPROFILE;
 };
 
+/**
+ * Check if filename is a tar archive by checking the extension.
+ * @return {Boolean} True if yes, else false.
+ */
+utils.isTarFile = function(filename) {
+  var exts = ['.tar', '.tar.gz', '.tar.bz2', '.tar.xz', '.tgz', '.tbz2', '.txz'],
+      endsWith = function (str, suffix) {
+        return str.indexOf(suffix, str.length - suffix.length) !== -1;
+      }
+
+  for (var i = 0; i < exts.length; i++) {
+    if (endsWith(filename, exts[i])) {
+      return true;
+    }
+  }
+
+  return false;
+};
 
 module.exports = utils;
diff --git a/package.json b/package.json
index 7f8286c..b4c5e54 100644
--- a/package.json
+++ b/package.json
@@ -1,7 +1,7 @@
 {
   "name": "grunt-dock",
   "description": "A grunt plugin to manage Docker",
-  "version": "1.0.1",
+  "version": "1.0.2",
   "license": "MIT",
   "author": "Johann Troendle",
   "maintainers": [
diff --git a/test/build.js b/test/build.js
index d17abf0..3811e55 100644
--- a/test/build.js
+++ b/test/build.js
@@ -64,7 +64,7 @@ describe("build", function() {
 
     stubs.buildImage = sinon.stub(docker, 'buildImage').yields('error', null);
 
-    build(grunt, docker, {images: {}}, function(e) {
+    build(grunt, docker, {images: {'test' : {dockerfile: null}}}, function(e) {
       expect(e).not.to.be.null;
       done();
     });