diff --git a/README.md b/README.md
index 8eec7ad..674ca33 100644
--- a/README.md
+++ b/README.md
@@ -498,8 +498,8 @@ fs.link("/data/logs/august", "/data/logs/current", function(err) {
 
 #### fs.exists(path, callback)<a name="exists"></a>
 
-Test whether or not the given path exists by checking with the file system. 
-Then call the callback argument with either true or false. 
+Test whether or not the given path exists by checking with the file system.
+Then call the callback argument with either true or false.
 
 Example:
 
@@ -596,7 +596,7 @@ Example:
 fs.mknod('/dir', 'DIRECTORY', function(err) {
   if(err) throw err;
   // /dir is now created
-  
+
   // Create a file inside /dir
   fs.mknod('/dir/myfile', 'FILE', function(err) {
     if(err) throw err;
@@ -897,7 +897,7 @@ fs.writeFile('/myfile', data, function (err) {
 
   fs.appendFile('/myfile', more, function (err) {
     if (err) throw err;
-    
+
     // '/myfile' would now contain [1, 2, 3, 4, 5, 6, 7, 8]
   });
 });
@@ -1088,20 +1088,31 @@ fs.writeFile('/data/subdir/file', 'data');
 ### FileSystemShell<a name="FileSystemShell"></a>
 
 Many common file system shell operations are available by using a `FileSystemShell` object.
-The `FileSystemShell` is obtained from, and used in conjuction with a `FileSystem`,
+The `FileSystemShell` is used in conjuction with a `FileSystem`,
 and provides augmented features. Many separate `FileSystemShell` objects can exist per
 `FileSystem`, but each `FileSystemShell` is bound to a single instance of a `FileSystem`
 for its lifetime.
 
-A `FileSystemShell` is created using the `FileSystem.Shell()` function:
+A `FileSystemShell` is created by calling `Filer.FileSystem().shell()`:
 
 ```javascript
 var fs = new Filer.FileSystem();
-var sh = fs.Shell(options);
-var sh2 = fs.Shell(options);
+var sh = fs.shell(options);
+var sh2 = fs.shell(options);
 // sh and sh2 are two separate shells, each bound to fs
 ```
 
+Or, the original object can be accessed through `Filer`:
+
+```javascript
+var fs = new Filer.FileSystem();
+var sh = fs.shell();
+
+Filer.Shell.prototype.newFunction = ...;
+
+sh.newFunction();
+```
+
 The `FileSystemShell` can take an optional `options` object. The `options` object
 can include `env`, which is a set of environment variables. Currently supported variables
 include `TMP` (the path to the temporary directory), and `PATH` (the list of known paths) and
@@ -1109,7 +1120,7 @@ others may be added in the future. You can also add your own, or update existing
 
 ```javascript
 var fs = new Filer.FileSystem();
-var sh = fs.Shell({
+var sh = fs.shell({
   env: {
     TMP: '/tempdir',
     PATH: '/one:/two'
@@ -1135,7 +1146,7 @@ Example:
 
 ```javascript
 var fs = new Filer.FileSystem();
-var sh = fs.Shell();
+var sh = fs.shell();
 var p = sh.env.get('PATH');
 
 // Store the current location
@@ -1155,7 +1166,7 @@ examples below assume a `FileSystemShell` instance named `sh` has been created l
 
 ```javascript
 var fs = new Filer.FileSystem();
-var sh = fs.Shell();
+var sh = fs.shell();
 ```
 
 * [sh.cd(path, callback)](#cd)
@@ -1360,9 +1371,9 @@ sh.tempDir(function(err, tmp) {
 
 #### sh.mkdirp(path, callback)<a name="mkdirp"></a>
 
-Recursively creates the directory at the provided path. If the 
+Recursively creates the directory at the provided path. If the
 directory already exists, no error is returned. All parents must
-be valid directories (not files). 
+be valid directories (not files).
 
 Example:
 
diff --git a/src/filesystem/interface.js b/src/filesystem/interface.js
index 93ea6f2..e9e54e1 100644
--- a/src/filesystem/interface.js
+++ b/src/filesystem/interface.js
@@ -87,6 +87,9 @@ function FileSystem(options, callback) {
   fs.stdout = STDOUT;
   fs.stderr = STDERR;
 
+  // Expose Shell constructor
+  this.Shell = Shell.bind(undefined, this);
+
   // Safely expose the list of open files and file
   // descriptor management functions
   var openFiles = {};
@@ -334,8 +337,4 @@ FileSystem.providers = providers;
   };
 });
 
-FileSystem.prototype.Shell = function(options) {
-  return new Shell(this, options);
-};
-
 module.exports = FileSystem;
diff --git a/src/index.js b/src/index.js
index f911644..d8e9f31 100644
--- a/src/index.js
+++ b/src/index.js
@@ -2,5 +2,6 @@ module.exports = {
   FileSystem: require('./filesystem/interface.js'),
   Buffer: require('./buffer.js'),
   Path: require('./path.js'),
-  Errors: require('./errors.js')
+  Errors: require('./errors.js'),
+  Shell: require('./shell/shell.js')
 };
diff --git a/tests/bugs/issue247.js b/tests/bugs/issue247.js
index 9fa5dd1..e69a45e 100644
--- a/tests/bugs/issue247.js
+++ b/tests/bugs/issue247.js
@@ -8,7 +8,7 @@ describe('sh.cd doesn\'t seem to be working from a relative path if I am one or
 
   it('should properly deal with relative paths missing ./ and ../', function(done) {
     var fs = util.fs();
-    var sh = fs.Shell();
+    var sh = new fs.Shell();
 
     sh.mkdirp('/home/scott', function(err) {
       if(err) throw err;
diff --git a/tests/bugs/ls-depth-bug.js b/tests/bugs/ls-depth-bug.js
index 3fa834b..ac2c5ae 100644
--- a/tests/bugs/ls-depth-bug.js
+++ b/tests/bugs/ls-depth-bug.js
@@ -9,7 +9,7 @@ describe('sh.ls and deep directory trees', function() {
 
   it('should not crash when calling sh.ls() on deep directory layouts', function(done) {
     var fs = util.fs();
-    var sh = fs.Shell();
+    var sh = new fs.Shell();
 
     var path = '';
     for(var i=0; i<50; i++) {
@@ -29,7 +29,7 @@ describe('sh.ls and deep directory trees', function() {
 
   it('should not crash when calling sh.ls() on wide directory layouts', function(done) {
     var fs = util.fs();
-    var sh = fs.Shell();
+    var sh = new fs.Shell();
 
     var dirName = '/dir';
 
diff --git a/tests/index.js b/tests/index.js
index ff930da..e997797 100644
--- a/tests/index.js
+++ b/tests/index.js
@@ -38,6 +38,7 @@ require("./spec/times.spec");
 require("./spec/time-flags.spec");
 require("./spec/fs.watch.spec");
 require("./spec/errors.spec");
+require("./spec/fs.shell.spec");
 
 // Filer.FileSystem.providers.*
 require("./spec/providers/providers.spec");
diff --git a/tests/lib/test-utils.js b/tests/lib/test-utils.js
index dc9e752..e8d4bde 100644
--- a/tests/lib/test-utils.js
+++ b/tests/lib/test-utils.js
@@ -85,7 +85,8 @@
   }
 
   function shell(options) {
-    return fs().Shell(options);
+    var _fs = fs();
+    return new _fs.Shell(options);
   }
 
   function cleanup(callback) {
diff --git a/tests/spec/filer.spec.js b/tests/spec/filer.spec.js
index 82ec707..82deb33 100644
--- a/tests/spec/filer.spec.js
+++ b/tests/spec/filer.spec.js
@@ -9,4 +9,8 @@ describe("Filer", function() {
   it("has FileSystem constructor", function() {
     expect(typeof Filer.FileSystem).to.equal('function');
   });
+
+  it("has Shell constructor", function() {
+    expect(typeof Filer.Shell).to.equal('function');
+  });
 });
diff --git a/tests/spec/fs.shell.spec.js b/tests/spec/fs.shell.spec.js
new file mode 100644
index 0000000..164e5ee
--- /dev/null
+++ b/tests/spec/fs.shell.spec.js
@@ -0,0 +1,33 @@
+var Filer = require('../..');
+var util = require('../lib/test-utils.js');
+var expect = require('chai').expect;
+
+describe("fs.shell", function() {
+  beforeEach(util.setup);
+  afterEach(util.cleanup);
+
+  it("is a function", function(done) {
+    var fs = util.fs();
+    expect(typeof fs.Shell).to.equal('function');
+
+    done();
+  });
+
+  it('should return a FileSystemShell instance', function(done) {
+    var fs = util.fs();
+    var sh = new fs.Shell();
+
+    expect(sh.prototype).to.deep.equal((new Filer.Shell(fs)).prototype);
+    done();
+  });
+
+  it('should reflect changes to the prototype', function(done){
+    var fs = util.fs();
+    var sh = new fs.Shell();
+
+    Filer.Shell.prototype.test = "foo";
+
+    expect(sh.test).to.equal("foo");
+    done();
+  });
+});
diff --git a/tests/spec/shell/cat.spec.js b/tests/spec/shell/cat.spec.js
index 52b8841..e7b6d67 100644
--- a/tests/spec/shell/cat.spec.js
+++ b/tests/spec/shell/cat.spec.js
@@ -13,7 +13,7 @@ describe('FileSystemShell.cat', function() {
 
   it('should fail when files argument is absent', function(done) {
     var fs = util.fs();
-    var shell = fs.Shell();
+    var shell = new fs.Shell();
 
     shell.cat(null, function(error, data) {
       expect(error).to.exist;
@@ -25,7 +25,7 @@ describe('FileSystemShell.cat', function() {
 
   it('should return the contents of a single file', function(done) {
     var fs = util.fs();
-    var shell = fs.Shell();
+    var shell = new fs.Shell();
     var contents = "file contents";
 
     fs.writeFile('/file', contents, function(err) {
@@ -41,7 +41,7 @@ describe('FileSystemShell.cat', function() {
 
   it('should return the contents of multiple files', function(done) {
     var fs = util.fs();
-    var shell = fs.Shell();
+    var shell = new fs.Shell();
     var contents = "file contents";
     var contents2 = contents + '\n' + contents;
 
@@ -62,7 +62,7 @@ describe('FileSystemShell.cat', function() {
 
   it('should fail if any of multiple file paths is invalid', function(done) {
     var fs = util.fs();
-    var shell = fs.Shell();
+    var shell = new fs.Shell();
     var contents = "file contents";
     var contents2 = contents + '\n' + contents;
 
diff --git a/tests/spec/shell/cd.spec.js b/tests/spec/shell/cd.spec.js
index c3fc43a..c45fbf8 100644
--- a/tests/spec/shell/cd.spec.js
+++ b/tests/spec/shell/cd.spec.js
@@ -18,7 +18,7 @@ describe('FileSystemShell.cd', function() {
 
   it('should allow changing the path to a valid dir', function(done) {
     var fs = util.fs();
-    var shell = fs.Shell();
+    var shell = new fs.Shell();
 
     fs.mkdir('/dir', function(err) {
       if(err) throw err;
@@ -34,7 +34,7 @@ describe('FileSystemShell.cd', function() {
 
   it('should fail when changing the path to an invalid dir', function(done) {
     var fs = util.fs();
-    var shell = fs.Shell();
+    var shell = new fs.Shell();
 
     fs.mkdir('/dir', function(err) {
       if(err) throw err;
@@ -51,7 +51,7 @@ describe('FileSystemShell.cd', function() {
 
   it('should fail when changing the path to a file', function(done) {
     var fs = util.fs();
-    var shell = fs.Shell();
+    var shell = new fs.Shell();
 
     fs.writeFile('/file', 'file', function(err) {
       if(err) throw err;
@@ -68,7 +68,7 @@ describe('FileSystemShell.cd', function() {
 
   it('should allow relative paths for a valid dir', function(done) {
     var fs = util.fs();
-    var shell = fs.Shell();
+    var shell = new fs.Shell();
 
     fs.mkdir('/dir', function(err) {
       if(err) throw err;
@@ -84,7 +84,7 @@ describe('FileSystemShell.cd', function() {
 
   it('should allow .. in paths for a valid dir', function(done) {
     var fs = util.fs();
-    var shell = fs.Shell();
+    var shell = new fs.Shell();
 
     fs.mkdir('/dir', function(err) {
       if(err) throw err;
@@ -111,7 +111,7 @@ describe('FileSystemShell.cd', function() {
       fs.symlink('/dir', '/link', function(error) {
         if(error) throw error;
 
-        var shell = fs.Shell();
+        var shell = new fs.Shell();
         shell.cd('link', function(error) {
           expect(error).not.to.exist;
           expect(shell.pwd()).to.equal('/link');
diff --git a/tests/spec/shell/env.spec.js b/tests/spec/shell/env.spec.js
index f231a08..5cf1c9e 100644
--- a/tests/spec/shell/env.spec.js
+++ b/tests/spec/shell/env.spec.js
@@ -34,7 +34,7 @@ describe('FileSystemShell.env', function() {
 
   it('should fail when dirs argument is absent', function(done) {
     var fs = util.fs();
-    var shell = fs.Shell();
+    var shell = new fs.Shell();
 
     shell.cat(null, function(error, list) {
       expect(error).to.exist;
@@ -46,7 +46,7 @@ describe('FileSystemShell.env', function() {
 
   it('should give new value for shell.pwd() when cwd changes', function(done) {
     var fs = util.fs();
-    var shell = fs.Shell();
+    var shell = new fs.Shell();
 
     fs.mkdir('/dir', function(err) {
       if(err) throw err;
@@ -62,7 +62,7 @@ describe('FileSystemShell.env', function() {
 
   it('should create/return the default tmp dir', function(done) {
     var fs = util.fs();
-    var shell = fs.Shell();
+    var shell = new fs.Shell();
 
     expect(shell.env.get('TMP')).to.equal('/tmp');
     shell.tempDir(function(err, tmp) {
@@ -77,7 +77,7 @@ describe('FileSystemShell.env', function() {
 
   it('should create/return the tmp dir specified in env.TMP', function(done) {
     var fs = util.fs();
-    var shell = fs.Shell({
+    var shell = new fs.Shell({
       env: {
         TMP: '/tempdir'
       }
@@ -96,7 +96,7 @@ describe('FileSystemShell.env', function() {
 
   it('should allow repeated calls to tempDir()', function(done) {
     var fs = util.fs();
-    var shell = fs.Shell();
+    var shell = new fs.Shell();
 
     expect(shell.env.get('TMP')).to.equal('/tmp');
     shell.tempDir(function(err, tmp) {
diff --git a/tests/spec/shell/exec.spec.js b/tests/spec/shell/exec.spec.js
index 1d5c620..ee94a42 100644
--- a/tests/spec/shell/exec.spec.js
+++ b/tests/spec/shell/exec.spec.js
@@ -13,7 +13,7 @@ describe('FileSystemShell.exec', function() {
 
   it('should be able to execute a command .js file from the filesystem', function(done) {
     var fs = util.fs();
-    var shell = fs.Shell();
+    var shell = new fs.Shell();
     var cmdString = "fs.writeFile(args[0], args[1], callback);";
 
     fs.writeFile('/cmd.js', cmdString, function(error) {
diff --git a/tests/spec/shell/ls.spec.js b/tests/spec/shell/ls.spec.js
index 713c96f..c9a718d 100644
--- a/tests/spec/shell/ls.spec.js
+++ b/tests/spec/shell/ls.spec.js
@@ -13,7 +13,7 @@ describe('FileSystemShell.ls', function() {
 
   it('should fail when dirs argument is absent', function(done) {
     var fs = util.fs();
-    var shell = fs.Shell();
+    var shell = new fs.Shell();
 
     shell.cat(null, function(error, list) {
       expect(error).to.exist;
@@ -25,7 +25,7 @@ describe('FileSystemShell.ls', function() {
 
   it('should return the contents of a simple dir', function(done) {
     var fs = util.fs();
-    var shell = fs.Shell();
+    var shell = new fs.Shell();
     var contents = "a";
     var contents2 = "bb";
 
@@ -63,7 +63,7 @@ describe('FileSystemShell.ls', function() {
 
   it('should return the shallow contents of a dir tree', function(done) {
     var fs = util.fs();
-    var shell = fs.Shell();
+    var shell = new fs.Shell();
     var contents = "a";
 
     fs.mkdir('/dir', function(err) {
@@ -119,7 +119,7 @@ describe('FileSystemShell.ls', function() {
 
   it('should return the deep contents of a dir tree', function(done) {
     var fs = util.fs();
-    var shell = fs.Shell();
+    var shell = new fs.Shell();
     var contents = "a";
 
     fs.mkdir('/dir', function(err) {
diff --git a/tests/spec/shell/mkdirp.spec.js b/tests/spec/shell/mkdirp.spec.js
index c9f574b..bbe6a04 100644
--- a/tests/spec/shell/mkdirp.spec.js
+++ b/tests/spec/shell/mkdirp.spec.js
@@ -13,7 +13,7 @@ describe('FileSystemShell.mkdirp', function() {
 
   it('should fail without a path provided', function(done) {
     var fs = util.fs();
-    var shell = fs.Shell();
+    var shell = new fs.Shell();
 
     shell.mkdirp(null, function(err) {
       expect(err).to.exist;
@@ -24,7 +24,7 @@ describe('FileSystemShell.mkdirp', function() {
 
   it('should succeed if provided path is root', function(done) {
     var fs = util.fs();
-    var shell = fs.Shell();
+    var shell = new fs.Shell();
     shell.mkdirp('/', function(err) {
       expect(err).to.not.exist;
       done();
@@ -33,7 +33,7 @@ describe('FileSystemShell.mkdirp', function() {
 
   it('should succeed if the directory exists', function(done) {
     var fs = util.fs();
-    var shell = fs.Shell();
+    var shell = new fs.Shell();
     fs.mkdir('/test', function(err){
       expect(err).to.not.exist;
       shell.mkdirp('/test',function(err) {
@@ -45,7 +45,7 @@ describe('FileSystemShell.mkdirp', function() {
 
   it('fail if a file name is provided', function(done) {
     var fs = util.fs();
-    var shell = fs.Shell();
+    var shell = new fs.Shell();
     fs.writeFile('/test.txt', 'test', function(err){
       expect(err).to.not.exist;
       shell.mkdirp('/test.txt', function(err) {
@@ -58,7 +58,7 @@ describe('FileSystemShell.mkdirp', function() {
 
   it('should succeed on a folder on root (\'/test\')', function(done) {
     var fs = util.fs();
-    var shell = fs.Shell();
+    var shell = new fs.Shell();
     shell.mkdirp('/test', function(err) {
       expect(err).to.not.exist;
       fs.exists('/test', function(dir){
@@ -70,7 +70,7 @@ describe('FileSystemShell.mkdirp', function() {
 
   it('should succeed on a folder with a nonexistant parent (\'/test/test\')', function(done) {
     var fs = util.fs();
-    var shell = fs.Shell();
+    var shell = new fs.Shell();
     shell.mkdirp('/test/test', function(err) {
       expect(err).to.not.exist;
       fs.exists('/test', function(dir1){
@@ -85,7 +85,7 @@ describe('FileSystemShell.mkdirp', function() {
 
   it('should fail on a folder with a file for its parent (\'/test.txt/test\')', function(done) {
     var fs = util.fs();
-    var shell = fs.Shell();
+    var shell = new fs.Shell();
     fs.writeFile('/test.txt', 'test', function(err){
       expect(err).to.not.exist;
       shell.mkdirp('/test.txt/test', function(err) {
diff --git a/tests/spec/shell/rm.spec.js b/tests/spec/shell/rm.spec.js
index b433655..0777460 100644
--- a/tests/spec/shell/rm.spec.js
+++ b/tests/spec/shell/rm.spec.js
@@ -13,7 +13,7 @@ describe('FileSystemShell.rm', function() {
 
   it('should fail when path argument is absent', function(done) {
     var fs = util.fs();
-    var shell = fs.Shell();
+    var shell = new fs.Shell();
 
     shell.rm(null, function(error, list) {
       expect(error).to.exist;
@@ -25,7 +25,7 @@ describe('FileSystemShell.rm', function() {
 
   it('should remove a single file', function(done) {
     var fs = util.fs();
-    var shell = fs.Shell();
+    var shell = new fs.Shell();
     var contents = "a";
 
     fs.writeFile('/file', contents, function(err) {
@@ -45,7 +45,7 @@ describe('FileSystemShell.rm', function() {
 
   it('should remove an empty dir', function(done) {
     var fs = util.fs();
-    var shell = fs.Shell();
+    var shell = new fs.Shell();
 
     fs.mkdir('/dir', function(err) {
       if(err) throw err;
@@ -64,7 +64,7 @@ describe('FileSystemShell.rm', function() {
 
   it('should fail to remove a non-empty dir', function(done) {
     var fs = util.fs();
-    var shell = fs.Shell();
+    var shell = new fs.Shell();
 
     fs.mkdir('/dir', function(err) {
       if(err) throw err;
@@ -83,7 +83,7 @@ describe('FileSystemShell.rm', function() {
 
   it('should remove a non-empty dir with option.recursive set', function(done) {
     var fs = util.fs();
-    var shell = fs.Shell();
+    var shell = new fs.Shell();
 
     fs.mkdir('/dir', function(err) {
       if(err) throw err;
@@ -106,7 +106,7 @@ describe('FileSystemShell.rm', function() {
 
   it('should work on a complex dir structure', function(done) {
     var fs = util.fs();
-    var shell = fs.Shell();
+    var shell = new fs.Shell();
     var contents = "a";
 
     fs.mkdir('/dir', function(err) {
diff --git a/tests/spec/shell/touch.spec.js b/tests/spec/shell/touch.spec.js
index 73a296e..e37bd6a 100644
--- a/tests/spec/shell/touch.spec.js
+++ b/tests/spec/shell/touch.spec.js
@@ -20,7 +20,7 @@ describe('FileSystemShell.touch', function() {
 
   it('should create a new file if path does not exist', function(done) {
     var fs = util.fs();
-    var shell = fs.Shell();
+    var shell = new fs.Shell();
 
     shell.touch('/newfile', function(error) {
       if(error) throw error;
@@ -35,7 +35,7 @@ describe('FileSystemShell.touch', function() {
 
   it('should skip creating a new file if options.updateOnly is true', function(done) {
     var fs = util.fs();
-    var shell = fs.Shell();
+    var shell = new fs.Shell();
 
     shell.touch('/newfile', { updateOnly: true }, function(error) {
       if(error) throw error;
@@ -49,7 +49,7 @@ describe('FileSystemShell.touch', function() {
 
   it('should update times if path does exist', function(done) {
     var fs = util.fs();
-    var shell = fs.Shell();
+    var shell = new fs.Shell();
     var atime = Date.parse('1 Oct 2000 15:33:22');
     var mtime = Date.parse('30 Sep 2000 06:43:54');
 
@@ -80,7 +80,7 @@ describe('FileSystemShell.touch', function() {
 
   it('should update times to specified date if path does exist', function(done) {
     var fs = util.fs();
-    var shell = fs.Shell();
+    var shell = new fs.Shell();
     var date = Date.parse('1 Oct 2001 15:33:22');
 
     fs.open('/newfile', 'w', function (error, fd) {