diff --git a/CHANGES/2423.bugfix b/CHANGES/2423.bugfix
new file mode 100644
index 00000000000..08823f4f69f
--- /dev/null
+++ b/CHANGES/2423.bugfix
@@ -0,0 +1 @@
+Fix connector convert OSError to ClientConnectorError
diff --git a/aiohttp/connector.py b/aiohttp/connector.py
index e70072148aa..47f8f3fb95b 100644
--- a/aiohttp/connector.py
+++ b/aiohttp/connector.py
@@ -785,6 +785,13 @@ def _create_direct_connection(self, req):
         sslcontext = self._get_ssl_context(req)
         fingerprint, hashfunc = self._get_fingerprint_and_hashfunc(req)
 
+        try:
+            hosts = yield from self._resolve_host(req.url.raw_host, req.port)
+        except OSError as exc:
+            # in case of proxy it is not ClientProxyConnectionError
+            # it is problem of resolving proxy ip itself
+            raise ClientConnectorError(req.connection_key, exc) from exc
+
         hosts = yield from self._resolve_host(req.url.raw_host, req.port)
 
         for hinfo in hosts:
@@ -938,6 +945,10 @@ def path(self):
 
     @asyncio.coroutine
     def _create_connection(self, req):
-        _, proto = yield from self._loop.create_unix_connection(
-            self._factory, self._path)
+        try:
+            _, proto = yield from self._loop.create_unix_connection(
+                self._factory, self._path)
+        except OSError as exc:
+            raise ClientConnectorError(req.connection_key, exc) from exc
+
         return proto
diff --git a/tests/test_connector.py b/tests/test_connector.py
index 68167174e68..2970a9aba8e 100644
--- a/tests/test_connector.py
+++ b/tests/test_connector.py
@@ -9,6 +9,7 @@
 import ssl
 import tempfile
 import unittest
+import uuid
 from unittest import mock
 
 import pytest
@@ -18,7 +19,7 @@
 from aiohttp import client, helpers, web
 from aiohttp.client import ClientRequest
 from aiohttp.connector import Connection, _DNSCacheTable
-from aiohttp.test_utils import unused_port
+from aiohttp.test_utils import make_mocked_coro, unused_port
 
 
 @pytest.fixture()
@@ -507,6 +508,19 @@ def test_tcp_connector_dns_throttle_requests_cancelled_when_close(
             yield from f
 
 
+def test_dns_error(loop):
+    connector = aiohttp.TCPConnector(loop=loop)
+    connector._resolve_host = make_mocked_coro(
+        raise_exception=OSError('dont take it serious'))
+
+    req = ClientRequest(
+        'GET', URL('http://www.python.org'),
+        loop=loop,
+    )
+    with pytest.raises(aiohttp.ClientConnectorError):
+        loop.run_until_complete(connector.connect(req))
+
+
 def test_get_pop_empty_conns(loop):
     # see issue #473
     conn = aiohttp.BaseConnector(loop=loop)
@@ -1281,6 +1295,34 @@ def handler(request):
     assert r.status == 200
 
 
+@pytest.mark.skipif(not hasattr(socket, 'AF_UNIX'),
+                    reason="requires unix socket")
+def test_unix_connector_not_found(loop):
+    connector = aiohttp.UnixConnector('/' + uuid.uuid4().hex, loop=loop)
+
+    req = ClientRequest(
+        'GET', URL('http://www.python.org'),
+        loop=loop,
+    )
+    with pytest.raises(aiohttp.ClientConnectorError):
+        loop.run_until_complete(connector.connect(req))
+
+
+@pytest.mark.skipif(not hasattr(socket, 'AF_UNIX'),
+                    reason="requires unix socket")
+def test_unix_connector_permission(loop):
+    loop.create_unix_connection = make_mocked_coro(
+        raise_exception=PermissionError())
+    connector = aiohttp.UnixConnector('/' + uuid.uuid4().hex, loop=loop)
+
+    req = ClientRequest(
+        'GET', URL('http://www.python.org'),
+        loop=loop,
+    )
+    with pytest.raises(aiohttp.ClientConnectorError):
+        loop.run_until_complete(connector.connect(req))
+
+
 def test_default_use_dns_cache(loop):
     conn = aiohttp.TCPConnector(loop=loop)
     assert conn.use_dns_cache
diff --git a/tests/test_proxy.py b/tests/test_proxy.py
index 9a0380f520f..ab123c05a56 100644
--- a/tests/test_proxy.py
+++ b/tests/test_proxy.py
@@ -215,7 +215,7 @@ def _test_connect_request_with_unicode_host(self, Request_mock):
         Request_mock.assert_called_with(mock.ANY, mock.ANY, "xn--9caa.com:80",
                                         mock.ANY, loop=loop)
 
-    def test_proxy_connection_error(self):
+    def test_proxy_dns_error(self):
         connector = aiohttp.TCPConnector(loop=self.loop)
         connector._resolve_host = make_mocked_coro(
             raise_exception=OSError('dont take it serious'))