diff --git a/README.md b/README.md
index b5aae7a..20c45b4 100644
--- a/README.md
+++ b/README.md
@@ -13,20 +13,20 @@ and in our case, from addon-sdk libraries :)
       arguments:   ['$@', '$ENV_TEST'],
       environment: ['ENV_TEST=OK'],
       
-      stdin: subprocess.WritablePipe(function() {
-        this.write("stdin");
-        this.close();
-      }),
-      stdout: subprocess.ReadablePipe(function(data) {
+      stdin: function(stdin) {
+        stdin.write("stdin");
+        stdin.close();
+      },
+      stdout: function(data) {
         // data should be equal to: "stdin OK"
         
-      }),
-      stderr: subprocess.ReadablePipe(function(data) {
+      },
+      stderr: function(data) {
         
-      }),
-      onFinished: subprocess.Terminate(function() {
-        
-      }),
+      },
+      done: function(result) {
+         console.log("process terminated with " + result.exitCode + "\n");
+      },
       mergeStderr: false
     });
 
diff --git a/lib/subprocess.js b/lib/subprocess.js
index 4ac9abe..8067a7d 100644
--- a/lib/subprocess.js
+++ b/lib/subprocess.js
@@ -333,7 +333,8 @@ function getPlatformValue(valueType) {
 
 var gDebugFunc = null,
     gLogFunc = null,
-    gXulRuntime = null;
+    gXulRuntime = null,
+    wrap = function (obj) {return obj;};
 
 function LogError(s) {
     if (gLogFunc)
@@ -464,6 +465,9 @@ var subprocess = {
     },
     registerLogHandler: function(func) {
         gLogFunc = func;
+    },
+    addWrapper: function (userWrapper) {
+        wrap = userWrapper;
     }
 };
 
@@ -1022,11 +1026,11 @@ function subprocess_win32(options) {
             setTimeout(function _done() {
                 if (options.done) {
                     try {
-                        options.done({
+                        options.done(wrap({
                             exitCode: exitCode,
                             stdout: output,
                             stderr: error,
-                        });
+                        }));
                     }
                     catch (ex) {
                         // prevent from blocking if options.done() throws an error
@@ -1053,14 +1057,14 @@ function subprocess_win32(options) {
 
         if(typeof(options.stdin) == 'function') {
             try {
-                options.stdin({
+                options.stdin(wrap({
                     write: function(data) {
                         writeStdin(data);
                     },
                     close: function() {
                         closeStdinHandle();
                     }
-                });
+                }));
             }
             catch (ex) {
                 // prevent from failing if options.stdin() throws an exception
@@ -1611,11 +1615,11 @@ function subprocess_unix(options) {
             setTimeout(function _done() {
                 if (options.done) {
                     try {
-                        options.done({
+                        options.done(wrap({
                             exitCode: exitCode,
                             stdout: output,
                             stderr: error,
-                        });
+                        }));
                     }
                     catch(ex) {
                         // prevent from blocking if options.done() throws an error
@@ -1647,14 +1651,14 @@ function subprocess_unix(options) {
         createStdinWriter();
         if(typeof(options.stdin) == 'function') {
             try {
-                options.stdin({
+                options.stdin(wrap({
                     write: function(data) {
                         writeStdin(data);
                     },
                     close: function() {
                         closeStdinHandle();
                     }
-                });
+                }));
             }
             catch(ex) {
                 // prevent from failing if options.stdin() throws an exception