diff --git a/IPython/html/static/notebook/js/comm.js b/IPython/html/static/notebook/js/comm.js
index 95da4b0..3633b74 100644
--- a/IPython/html/static/notebook/js/comm.js
+++ b/IPython/html/static/notebook/js/comm.js
@@ -61,16 +61,15 @@ var IPython = (function (IPython) {
     
     CommManager.prototype.comm_open = function (msg) {
         var content = msg.content;
-        var callback = this.targets[content.target_name];
-        if (callback === undefined) {
+        var f = this.targets[content.target_name];
+        if (f === undefined) {
             console.log("No such target registered: ", content.target_name);
             console.log("Available targets are: ", this.targets);
             return;
         }
         var comm = new Comm(content.comm_id);
         this.register_comm(comm);
-        callback(comm);
-        comm.handle_open(msg);
+        f(comm, msg);
     };
     
     CommManager.prototype.comm_close = function (msg) {
@@ -99,7 +98,7 @@ var IPython = (function (IPython) {
     var Comm = function (comm_id, target_name) {
         this.comm_id = comm_id || new IPython.utils.uuid();
         this.target_name = target_name;
-        this._msg_callback = this._open_callback = this._close_callback = null;
+        this._msg_callback = this._close_callback = null;
     };
     
     // methods for sending messages
@@ -133,10 +132,6 @@ var IPython = (function (IPython) {
         this['_' + key + '_callback'] = callback;
     };
     
-    Comm.prototype.on_open = function (callback) {
-        this._register_callback('open', callback);
-    };
-    
     Comm.prototype.on_msg = function (callback) {
         this._register_callback('msg', callback);
     };
@@ -152,10 +147,6 @@ var IPython = (function (IPython) {
         if (callback) callback(msg);
     };
     
-    Comm.prototype.handle_open = function (msg) {
-        this._maybe_callback('open', msg);
-    };
-    
     Comm.prototype.handle_msg = function (msg) {
         this._maybe_callback('msg', msg);
     };
diff --git a/IPython/kernel/comm/comm.py b/IPython/kernel/comm/comm.py
index 1e94c3a..16a7d61 100644
--- a/IPython/kernel/comm/comm.py
+++ b/IPython/kernel/comm/comm.py
@@ -43,10 +43,9 @@ class Comm(LoggingConfigurable):
     def _topic_default(self):
         return ('comm-%s' % self.comm_id).encode('ascii')
     
-    _open_data = Dict(help="data dict, if any, to be included in comm_close")
+    _open_data = Dict(help="data dict, if any, to be included in comm_open")
     _close_data = Dict(help="data dict, if any, to be included in comm_close")
     
-    _open_callback = Any()
     _msg_callback = Any()
     _close_callback = Any()
     
@@ -61,7 +60,7 @@ class Comm(LoggingConfigurable):
         super(Comm, self).__init__(**kwargs)
         get_ipython().comm_manager.register_comm(self)
         if self.primary:
-            # I am primary, open my peer
+            # I am primary, open my peer.
             self.open(data)
     
     def _publish_msg(self, msg_type, data=None, **keys):
@@ -99,14 +98,6 @@ class Comm(LoggingConfigurable):
         self._publish_msg('comm_msg', data)
     
     # registering callbacks
-    def on_open(self, callback):
-        """Register a callback for comm_open
-        
-        Will be called with the `data` of the open message.
-        
-        Call `on_open(None)` to disable an existing callback.
-        """
-        self._open_callback = callback
     
     def on_close(self, callback):
         """Register a callback for comm_close
@@ -128,12 +119,6 @@ class Comm(LoggingConfigurable):
     
     # handling of incoming messages
     
-    def handle_open(self, msg):
-        """Handle a comm_open message"""
-        self.log.debug("handle_open[%s](%s)", self.comm_id, msg)
-        if self._open_callback:
-            self._open_callback(msg)
-    
     def handle_close(self, msg):
         """Handle a comm_close message"""
         self.log.debug("handle_close[%s](%s)", self.comm_id, msg)
diff --git a/IPython/kernel/comm/manager.py b/IPython/kernel/comm/manager.py
index 75e24a7..315209f 100644
--- a/IPython/kernel/comm/manager.py
+++ b/IPython/kernel/comm/manager.py
@@ -136,9 +136,8 @@ class CommManager(LoggingConfigurable):
             self.log.error("No such comm target registered: %s", target_name)
             comm.close()
             return
-        f(comm)
-        comm.handle_open(msg)
         self.register_comm(comm)
+        f(comm, msg)
     
     @with_output
     def comm_msg(self, stream, ident, msg):