diff --git a/patroni/postmaster.py b/patroni/postmaster.py
index 0fd068ef..8debeaaf 100644
--- a/patroni/postmaster.py
+++ b/patroni/postmaster.py
@@ -102,28 +102,31 @@ class PostmasterProcess(psutil.Process):
         return None
 
     def wait_for_user_backends_to_close(self):
-        # These regexps are cross checked against versions PostgreSQL 9.1 .. 9.6
-        aux_proc_re = re.compile("(?:postgres:)( .*:)? (?:""(?:startup|logger|checkpointer|writer|wal writer|"
-                                 "autovacuum launcher|autovacuum worker|stats collector|wal receiver|archiver|"
-                                 "wal sender) process|bgworker: )")
+        # These regexps are cross checked against versions PostgreSQL 9.1 .. 11
+        aux_proc_re = re.compile("(?:postgres:)( .*:)? (?:(?:archiver|startup|autovacuum launcher|autovacuum worker|"
+                                 "checkpointer|logger|stats collector|wal receiver|wal writer|writer)(?: process  )?|"
+                                 "walreceiver|wal sender process|walsender|walwriter|background writer|"
+                                 "logical replication launcher|logical replication worker for|bgworker:) ")
 
         try:
-            user_backends = []
-            user_backends_cmdlines = []
-            for child in self.children():
-                try:
-                    cmdline = child.cmdline()[0]
-                    if not aux_proc_re.match(cmdline):
-                        user_backends.append(child)
-                        user_backends_cmdlines.append(cmdline)
-                except psutil.NoSuchProcess:
-                    pass
-            if user_backends:
-                logger.debug('Waiting for user backends %s to close', ', '.join(user_backends_cmdlines))
-                psutil.wait_procs(user_backends)
-            logger.debug("Backends closed")
+            children = self.children()
         except psutil.Error:
-            logger.exception('wait_for_user_backends_to_close')
+            return logger.debug('Failed to get list of postmaster children')
+
+        user_backends = []
+        user_backends_cmdlines = []
+        for child in children:
+            try:
+                cmdline = child.cmdline()[0]
+                if not aux_proc_re.match(cmdline):
+                    user_backends.append(child)
+                    user_backends_cmdlines.append(cmdline)
+            except psutil.NoSuchProcess:
+                pass
+        if user_backends:
+            logger.debug('Waiting for user backends %s to close', ', '.join(user_backends_cmdlines))
+            psutil.wait_procs(user_backends)
+        logger.debug("Backends closed")
 
     @staticmethod
     def start(pgcommand, data_dir, conf, options):
diff --git a/tests/test_postmaster.py b/tests/test_postmaster.py
index 86172525..ee951c64 100644
--- a/tests/test_postmaster.py
+++ b/tests/test_postmaster.py
@@ -67,7 +67,7 @@ class TestPostmasterProcess(unittest.TestCase):
     @patch('psutil.wait_procs')
     def test_wait_for_user_backends_to_close(self, mock_wait):
         c1 = Mock()
-        c1.cmdline = Mock(return_value=["postgres: startup process"])
+        c1.cmdline = Mock(return_value=["postgres: startup process   "])
         c2 = Mock()
         c2.cmdline = Mock(return_value=["postgres: postgres postgres [local] idle"])
         c3 = Mock()
@@ -77,8 +77,7 @@ class TestPostmasterProcess(unittest.TestCase):
             self.assertIsNone(proc.wait_for_user_backends_to_close())
             mock_wait.assert_called_with([c2])
 
-        c3.cmdline = Mock(side_effect=psutil.AccessDenied(123))
-        with patch('psutil.Process.children', Mock(return_value=[c3])):
+        with patch('psutil.Process.children', Mock(side_effect=psutil.NoSuchProcess(123))):
             proc = PostmasterProcess(123)
             self.assertIsNone(proc.wait_for_user_backends_to_close())