diff --git a/patroni/etcd.py b/patroni/etcd.py
index 93ef2a2c1..d84f5a50d 100644
--- a/patroni/etcd.py
+++ b/patroni/etcd.py
@@ -52,7 +52,11 @@ def machines(self):
     def api_execute(self, path, method, **kwargs):
         # Update machines_cache if previous attempt of update has failed
         self._update_machines_cache and self._load_machines_cache()
-        return super(Client, self).api_execute(path, method, **kwargs)
+        try:
+            return super(Client, self).api_execute(path, method, **kwargs)
+        except etcd.EtcdConnectionFailed:
+            self._update_machines_cache = True
+            raise
 
     @staticmethod
     def get_srv_record(host):
diff --git a/tests/test_etcd.py b/tests/test_etcd.py
index 53c054e56..d0d01d71f 100644
--- a/tests/test_etcd.py
+++ b/tests/test_etcd.py
@@ -106,13 +106,13 @@ def etcd_read(key, **kwargs):
                  "modifiedIndex": 20437, "createdIndex": 20437},
                 {"key": "/service/batman5/members", "dir": True, "nodes": [
                     {"key": "/service/batman5/members/postgresql1",
-                     "value": "postgres://replicator:rep-pass@127.0.0.1:5434/postgres"
-                        + "?application_name=http://127.0.0.1:8009/patroni",
+                     "value": "postgres://replicator:rep-pass@127.0.0.1:5434/postgres" +
+                        "?application_name=http://127.0.0.1:8009/patroni",
                      "expiration": "2015-05-15T09:10:59.949384522Z", "ttl": 21,
                      "modifiedIndex": 20727, "createdIndex": 20727},
                     {"key": "/service/batman5/members/postgresql0",
-                     "value": "postgres://replicator:rep-pass@127.0.0.1:5433/postgres"
-                        + "?application_name=http://127.0.0.1:8008/patroni",
+                     "value": "postgres://replicator:rep-pass@127.0.0.1:5433/postgres" +
+                        "?application_name=http://127.0.0.1:8008/patroni",
                      "expiration": "2015-05-15T09:11:09.611860899Z", "ttl": 30,
                      "modifiedIndex": 20730, "createdIndex": 20730}],
                  "modifiedIndex": 1581, "createdIndex": 1581}], "modifiedIndex": 1581, "createdIndex": 1581}}
@@ -165,6 +165,11 @@ def test_api_execute(self):
         self.client._base_uri = 'http://localhost:4001'
         self.client._machines_cache = ['http://localhost:2379']
         self.client.api_execute('/', 'GET')
+        self.client._update_machines_cache = False
+        self.client._base_uri = 'http://localhost:4001'
+        self.client._machines_cache = []
+        self.assertRaises(etcd.EtcdConnectionFailed, self.client.api_execute, '/', 'GET')
+        self.assertTrue(self.client._update_machines_cache)
 
     def test_get_srv_record(self):
         self.assertEquals(self.client.get_srv_record('blabla'), [])
diff --git a/tests/test_postgresql.py b/tests/test_postgresql.py
index 4d2f2dd0b..83e93ec04 100644
--- a/tests/test_postgresql.py
+++ b/tests/test_postgresql.py
@@ -4,12 +4,7 @@
 import shutil
 import unittest
 
-from sys import version_info
-if version_info.major == 2:
-    import __builtin__ as builtins
-else:
-    import builtins
-
+from six.moves import builtins
 from mock import Mock, MagicMock, PropertyMock, patch, mock_open
 from patroni.dcs import Cluster, Leader, Member
 from patroni.exceptions import PostgresException, PostgresConnectionException
@@ -146,10 +141,10 @@ def pg_controldata_string(*args, **kwargs):
 
 
 def postmaster_opts_string(*args, **kwargs):
-    return '/usr/local/pgsql/bin/postgres "-D" "data/postgresql0" "--listen_addresses=127.0.0.1" "--port=5432"'\
-        ' "--hot_standby=on" "--wal_keep_segments=8" "--wal_level=hot_standby" "--archive_command=mkdir -p ../wal_archive \n'\
-        '&& cp %p ../wal_archive/%f" "--wal_log_hints=on" "--max_wal_senders=5" "--archive_timeout=1800s" "--archive_mode=on"'\
-        ' "--max_replication_slots=5"\n'
+    return '/usr/local/pgsql/bin/postgres "-D" "data/postgresql0" "--listen_addresses=127.0.0.1" \
+"--port=5432" "--hot_standby=on" "--wal_keep_segments=8" "--wal_level=hot_standby" \
+"--archive_command=mkdir -p ../wal_archive && cp %p ../wal_archive/%f" "--wal_log_hints=on" \
+"--max_wal_senders=5" "--archive_timeout=1800s" "--archive_mode=on" "--max_replication_slots=5"\n'
 
 
 def psycopg2_connect(*args, **kwargs):
diff --git a/tests/test_utils.py b/tests/test_utils.py
index 45b194dcd..265f98ab0 100644
--- a/tests/test_utils.py
+++ b/tests/test_utils.py
@@ -67,7 +67,9 @@ def test_deadline(self):
         self.assertRaises(RetryFailedError, retry, self._fail(times=100))
 
     def test_copy(self):
-        _sleep = lambda t: None
+        def _sleep(t):
+            None
+
         retry = self._makeOne(sleep_func=_sleep)
         rcopy = retry.copy()
         self.assertTrue(rcopy.sleep_func is _sleep)