diff --git a/node/node-tests.ts b/node/node-tests.ts
index 49b43302b..397a9dfa4 100644
--- a/node/node-tests.ts
+++ b/node/node-tests.ts
@@ -21,7 +21,9 @@ assert.doesNotThrow(() => {
     if (false) { throw "a hammer at your face"; }
 }, undefined, "What the...*crunch*");
 
-
+////////////////////////////////////////////////////
+/// File system tests : http://nodejs.org/api/fs.html
+////////////////////////////////////////////////////
 fs.writeFile("thebible.txt",
     "Do unto others as you would have them do unto you.",
     assert.ifError);
@@ -33,6 +35,18 @@ fs.writeFile("Harry Potter",
     },
     assert.ifError);
 
+var content: string,
+    buffer: NodeBuffer;
+
+content = fs.readFileSync('testfile', 'utf8');
+content = fs.readFileSync('testfile', {encoding : 'utf8'});
+buffer = fs.readFileSync('testfile');
+buffer = fs.readFileSync('testfile', {flag : 'r'});
+fs.readFile('testfile', 'utf8', (err, data) => content = data);
+fs.readFile('testfile', {encoding : 'utf8'}, (err, data) => content = data);
+fs.readFile('testfile', (err, data) => buffer = data);
+fs.readFile('testfile', {flag : 'r'}, (err, data) => buffer = data);
+
 class Networker extends events.EventEmitter {
     constructor() {
         super();
@@ -65,4 +79,4 @@ function stream_readable_pipe_test() {
     var z = zlib.createGzip();
     var w = fs.createWriteStream('file.txt.gz');
     r.pipe(z).pipe(w);
-}
\ No newline at end of file
+}
diff --git a/node/node.d.ts b/node/node.d.ts
index fe7fbd324..a0473ad8b 100644
--- a/node/node.d.ts
+++ b/node/node.d.ts
@@ -848,10 +848,13 @@ declare module "fs" {
     export function writeSync(fd: number, buffer: NodeBuffer, offset: number, length: number, position: number): number;
     export function read(fd: number, buffer: NodeBuffer, offset: number, length: number, position: number, callback?: (err: ErrnoException, bytesRead: number, buffer: NodeBuffer) => void): void;
     export function readSync(fd: number, buffer: NodeBuffer, offset: number, length: number, position: number): number;
-    export function readFile(filename: string, options: { encoding?: string; flag?: string; }, callback: (err: ErrnoException, data: any) => void): void;
+    export function readFile(filename: string, encoding: string, callback: (err: ErrnoException, data: string) => void): void;
+    export function readFile(filename: string, options: { encoding: string; flag?: string; }, callback: (err: ErrnoException, data: string) => void): void;
+    export function readFile(filename: string, options: { flag?: string; }, callback: (err: ErrnoException, data: NodeBuffer) => void): void;
     export function readFile(filename: string, callback: (err: ErrnoException, data: NodeBuffer) => void ): void;
-    export function readFileSync(filename: string, options?: { flag?: string; }): NodeBuffer;
+    export function readFileSync(filename: string, encoding: string): string;
     export function readFileSync(filename: string, options: { encoding: string; flag?: string; }): string;
+    export function readFileSync(filename: string, options?: { flag?: string; }): NodeBuffer;
     export function writeFile(filename: string, data: any, callback?: (err: ErrnoException) => void): void;
     export function writeFile(filename: string, data: any, options: { encoding?: string; mode?: number; flag?: string; }, callback?: (err: ErrnoException) => void): void;
     export function writeFile(filename: string, data: any, options: { encoding?: string; mode?: string; flag?: string; }, callback?: (err: ErrnoException) => void): void;