diff --git a/gns3server/modules/port_manager.py b/gns3server/modules/port_manager.py
index 4ea2cac5..26b2c990 100644
--- a/gns3server/modules/port_manager.py
+++ b/gns3server/modules/port_manager.py
@@ -18,6 +18,7 @@
 import socket
 import ipaddress
 import asyncio
+from aiohttp.web import HTTPConflict
 
 
 class PortManager:
@@ -146,10 +147,10 @@ class PortManager:
                 else:
                     continue
 
-        raise Exception("Could not find a free port between {} and {} on host {}, last exception: {}".format(start_port,
-                                                                                                             end_port,
-                                                                                                             host,
-                                                                                                             last_exception))
+        raise HTTPConflict(reason="Could not find a free port between {} and {} on host {}, last exception: {}".format(start_port,
+                                                                                                                       end_port,
+                                                                                                                       host,
+                                                                                                                       last_exception))
 
     def get_free_console_port(self):
         """
@@ -173,7 +174,7 @@ class PortManager:
         """
 
         if port in self._used_tcp_ports:
-            raise Exception("TCP port already {} in use on host".format(port, self._host))
+            raise HTTPConflict(reason="TCP port already {} in use on host".format(port, self._console_host))
         self._used_tcp_ports.add(port)
 
     def release_console_port(self, port):
diff --git a/tests/modules/test_port_manager.py b/tests/modules/test_port_manager.py
new file mode 100644
index 00000000..e5a86ea8
--- /dev/null
+++ b/tests/modules/test_port_manager.py
@@ -0,0 +1,27 @@
+# -*- coding: utf-8 -*-
+#
+# Copyright (C) 2015 GNS3 Technologies Inc.
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+import aiohttp
+import pytest
+from gns3server.modules.port_manager import PortManager
+
+
+def test_reserve_console_port():
+    pm = PortManager.instance()
+    pm.reserve_console_port(4242)
+    with pytest.raises(aiohttp.web.HTTPConflict):
+        pm.reserve_console_port(4242)