diff --git a/vcsserver/tests/test_hooks.py b/vcsserver/tests/test_hooks.py
--- a/vcsserver/tests/test_hooks.py
+++ b/vcsserver/tests/test_hooks.py
@@ -25,6 +25,7 @@ import mercurial.ui
 import mock
 import pytest
 
+from vcsserver.hooks import HooksHttpClient
 from vcsserver.lib.rc_json import json
 from vcsserver import hooks
 
@@ -243,3 +244,43 @@ class MirrorHttpServer(object):
     @property
     def uri(self):
         return '{}:{}'.format(self.ip_address, self.port)
+
+
+def test_hooks_http_client_init():
+    hooks_uri = 'http://localhost:8000'
+    client = HooksHttpClient(hooks_uri)
+    assert client.hooks_uri == hooks_uri
+
+
+def test_hooks_http_client_call():
+    hooks_uri = 'http://localhost:8000'
+
+    method = 'test_method'
+    extras = {'key': 'value'}
+
+    with \
+        mock.patch('vcsserver.hooks.HTTPConnection') as mock_connection,\
+        mock.patch('msgpack.load') as mock_load:
+
+        client = HooksHttpClient(hooks_uri)
+
+        mock_load.return_value = {'result': 'success'}
+        response = mock.MagicMock()
+        response.status = 200
+        mock_connection.request.side_effect = None
+        mock_connection.getresponse.return_value = response
+
+        result = client(method, extras)
+
+        mock_connection.assert_called_with(hooks_uri)
+        mock_connection.return_value.request.assert_called_once()
+        assert result == {'result': 'success'}
+
+
+def test_hooks_http_client_serialize():
+    method = 'test_method'
+    extras = {'key': 'value'}
+    headers, body = HooksHttpClient._serialize(method, extras)
+
+    assert headers == {'rc-hooks-protocol': HooksHttpClient.proto}
+    assert msgpack.unpackb(body) == {'method': method, 'extras': extras}