diff --git a/src/tcp_wrap.cc b/src/tcp_wrap.cc
index 8a199bd7b69..9de6c79f10a 100644
--- a/src/tcp_wrap.cc
+++ b/src/tcp_wrap.cc
@@ -58,8 +58,6 @@ static size_t slab_used;
 static uv_tcp_t* handle_that_last_alloced;
 
 static Persistent<String> slab_sym;
-static Persistent<String> offset_sym;
-static Persistent<String> length_sym;
 static Persistent<String> buffer_sym;
 
 class TCPWrap;
@@ -104,8 +102,6 @@ class TCPWrap {
     constructor = Persistent<Function>::New(t->GetFunction());
 
     slab_sym = Persistent<String>::New(String::NewSymbol("slab"));
-    offset_sym = Persistent<String>::New(String::NewSymbol("offset"));
-    length_sym = Persistent<String>::New(String::NewSymbol("length"));
     buffer_sym = Persistent<String>::New(String::NewSymbol("buffer"));
 
     target->Set(String::NewSymbol("TCP"), constructor);
@@ -313,17 +309,15 @@ class TCPWrap {
     }
 
     if (nread > 0) {
-      Local<Object> slice = Object::New();
-      slice->Set(slab_sym, slab_v);
-      slice->Set(offset_sym, Integer::New(wrap->slab_offset_));
-      slice->Set(length_sym, Integer::New(nread));
-
-      Local<Value> argv[1] = { slice };
-      MakeCallback(wrap->object_, "onread", 1, argv);
+      Local<Value> argv[3] = {
+        slab_v,
+        Integer::New(wrap->slab_offset_),
+        Integer::New(nread)
+      };
+      MakeCallback(wrap->object_, "onread", 3, argv);
     }
   }
 
-
   // TODO: share me?
   static Handle<Value> Close(const Arguments& args) {
     HandleScope scope;
@@ -352,8 +346,13 @@ class TCPWrap {
       SetErrno(uv_last_error().code);
     }
 
-    Local<Value> argv[1] = { Local<Value>::New(wrap->object_) };
-    MakeCallback(req_wrap->object_, "oncomplete", 1, argv);
+    Local<Value> argv[3] = {
+      Local<Value>::New(wrap->object_),
+      Local<Value>::New(req_wrap->object_),
+      req_wrap->object_->GetHiddenValue(buffer_sym),
+    };
+ 
+    MakeCallback(req_wrap->object_, "oncomplete", 3, argv);
 
     delete req_wrap;
   }
diff --git a/test/simple/test-tcp-wrap-listen.js b/test/simple/test-tcp-wrap-listen.js
index 608b13616bd..6ada670edf5 100644
--- a/test/simple/test-tcp-wrap-listen.js
+++ b/test/simple/test-tcp-wrap-listen.js
@@ -27,13 +27,21 @@ server.onconnection = function(client) {
 
   client.readStart();
   client.pendingWrites = [];
-  client.onread = function(s) {
-    if (s) {
-      slice = s;
-      var req = client.write(s.slab, s.offset, s.length);
+  client.onread = function(buffer, offset, length) {
+    if (buffer) {
+      assert.ok(length > 0);
+
+      var req = client.write(buffer, offset, length);
       client.pendingWrites.push(req);
-      req.oncomplete = function() {
+
+      req.oncomplete = function(client_, req_, buffer_) {
         assert.equal(req, client.pendingWrites.shift());
+
+        // Check parameters.
+        assert.equal(client, client_);
+        assert.equal(req, req_);
+        assert.equal(buffer, buffer_);
+
         writeCount++;
         console.log("write " + writeCount);
         maybeCloseClient();
@@ -72,11 +80,6 @@ process.on('exit', function() {
   assert.equal(1, eofCount);
   assert.equal(1, writeCount);
   assert.equal(1, recvCount);
-  assert.ok(slice);
-  assert.ok(slice.slab);
-
-  var s = slice.slab.slice(slice.offset, slice.length, "ascii");
-  assert.equal("hello world", s);
 });