diff --git a/src/socketio/asyncio_namespace.py b/src/socketio/asyncio_namespace.py
index f95ec23..eba8838 100644
--- a/src/socketio/asyncio_namespace.py
+++ b/src/socketio/asyncio_namespace.py
@@ -41,7 +41,7 @@ class AsyncNamespace(namespace.Namespace):
                 ret = handler(*args)
             return ret
 
-    async def emit(self, event, data=None, room=None, skip_sid=None,
+    async def emit(self, event, data=None, to=None, room=None, skip_sid=None,
                    namespace=None, callback=None):
         """Emit a custom event to one or more connected clients.
 
@@ -51,13 +51,13 @@ class AsyncNamespace(namespace.Namespace):
 
         Note: this method is a coroutine.
         """
-        return await self.server.emit(event, data=data, room=room,
+        return await self.server.emit(event, data=data, to=to, room=room,
                                       skip_sid=skip_sid,
                                       namespace=namespace or self.namespace,
                                       callback=callback)
 
-    async def send(self, data, room=None, skip_sid=None, namespace=None,
-                   callback=None):
+    async def send(self, data, to=None, room=None, skip_sid=None,
+                   namespace=None, callback=None):
         """Send a message to one or more connected clients.
 
         The only difference with the :func:`socketio.Server.send` method is
@@ -66,7 +66,8 @@ class AsyncNamespace(namespace.Namespace):
 
         Note: this method is a coroutine.
         """
-        return await self.server.send(data, room=room, skip_sid=skip_sid,
+        return await self.server.send(data, to=to, room=room,
+                                      skip_sid=skip_sid,
                                       namespace=namespace or self.namespace,
                                       callback=callback)
 
diff --git a/src/socketio/namespace.py b/src/socketio/namespace.py
index 97be4ee..4e1ec79 100644
--- a/src/socketio/namespace.py
+++ b/src/socketio/namespace.py
@@ -37,19 +37,20 @@ class Namespace(BaseNamespace):
     def _set_server(self, server):
         self.server = server
 
-    def emit(self, event, data=None, room=None, skip_sid=None, namespace=None,
-             callback=None):
+    def emit(self, event, data=None, to=None, room=None, skip_sid=None,
+             namespace=None, callback=None):
         """Emit a custom event to one or more connected clients.
 
         The only difference with the :func:`socketio.Server.emit` method is
         that when the ``namespace`` argument is not given the namespace
         associated with the class is used.
         """
-        return self.server.emit(event, data=data, room=room, skip_sid=skip_sid,
+        return self.server.emit(event, data=data, to=to, room=room,
+                                skip_sid=skip_sid,
                                 namespace=namespace or self.namespace,
                                 callback=callback)
 
-    def send(self, data, room=None, skip_sid=None, namespace=None,
+    def send(self, data, to=None, room=None, skip_sid=None, namespace=None,
              callback=None):
         """Send a message to one or more connected clients.
 
@@ -57,7 +58,7 @@ class Namespace(BaseNamespace):
         that when the ``namespace`` argument is not given the namespace
         associated with the class is used.
         """
-        return self.server.send(data, room=room, skip_sid=skip_sid,
+        return self.server.send(data, to=to, room=room, skip_sid=skip_sid,
                                 namespace=namespace or self.namespace,
                                 callback=callback)
 
diff --git a/tests/asyncio/test_asyncio_namespace.py b/tests/asyncio/test_asyncio_namespace.py
index b2ebfd0..aa73f5f 100644
--- a/tests/asyncio/test_asyncio_namespace.py
+++ b/tests/asyncio/test_asyncio_namespace.py
@@ -93,13 +93,14 @@ class TestAsyncNamespace(unittest.TestCase):
         ns._set_server(mock_server)
         _run(
             ns.emit(
-                'ev', data='data', room='room', skip_sid='skip', callback='cb'
+                'ev', data='data', to='room', skip_sid='skip', callback='cb'
             )
         )
         ns.server.emit.mock.assert_called_with(
             'ev',
             data='data',
-            room='room',
+            to='room',
+            room=None,
             skip_sid='skip',
             namespace='/foo',
             callback='cb',
@@ -117,6 +118,7 @@ class TestAsyncNamespace(unittest.TestCase):
         ns.server.emit.mock.assert_called_with(
             'ev',
             data='data',
+            to=None,
             room='room',
             skip_sid='skip',
             namespace='/bar',
@@ -128,10 +130,11 @@ class TestAsyncNamespace(unittest.TestCase):
         mock_server = mock.MagicMock()
         mock_server.send = AsyncMock()
         ns._set_server(mock_server)
-        _run(ns.send(data='data', room='room', skip_sid='skip', callback='cb'))
+        _run(ns.send(data='data', to='room', skip_sid='skip', callback='cb'))
         ns.server.send.mock.assert_called_with(
             'data',
-            room='room',
+            to='room',
+            room=None,
             skip_sid='skip',
             namespace='/foo',
             callback='cb',
@@ -147,6 +150,7 @@ class TestAsyncNamespace(unittest.TestCase):
         )
         ns.server.send.mock.assert_called_with(
             'data',
+            to=None,
             room='room',
             skip_sid='skip',
             namespace='/bar',
diff --git a/tests/common/test_namespace.py b/tests/common/test_namespace.py
index 1478c97..e42f864 100644
--- a/tests/common/test_namespace.py
+++ b/tests/common/test_namespace.py
@@ -56,11 +56,12 @@ class TestNamespace(unittest.TestCase):
     def test_emit(self):
         ns = namespace.Namespace('/foo')
         ns._set_server(mock.MagicMock())
-        ns.emit('ev', data='data', room='room', skip_sid='skip', callback='cb')
+        ns.emit('ev', data='data', to='room', skip_sid='skip', callback='cb')
         ns.server.emit.assert_called_with(
             'ev',
             data='data',
-            room='room',
+            to='room',
+            room=None,
             skip_sid='skip',
             namespace='/foo',
             callback='cb',
@@ -76,6 +77,7 @@ class TestNamespace(unittest.TestCase):
         ns.server.emit.assert_called_with(
             'ev',
             data='data',
+            to=None,
             room='room',
             skip_sid='skip',
             namespace='/bar',
@@ -85,10 +87,11 @@ class TestNamespace(unittest.TestCase):
     def test_send(self):
         ns = namespace.Namespace('/foo')
         ns._set_server(mock.MagicMock())
-        ns.send(data='data', room='room', skip_sid='skip', callback='cb')
+        ns.send(data='data', to='room', skip_sid='skip', callback='cb')
         ns.server.send.assert_called_with(
             'data',
-            room='room',
+            to='room',
+            room=None,
             skip_sid='skip',
             namespace='/foo',
             callback='cb',
@@ -102,6 +105,7 @@ class TestNamespace(unittest.TestCase):
         )
         ns.server.send.assert_called_with(
             'data',
+            to=None,
             room='room',
             skip_sid='skip',
             namespace='/bar',