--- ./patroni/postmaster.py	2018-09-26 13:58:59.000000000 +0200
+++ ./patroni/postmaster.py_	2018-09-26 13:58:54.567944491 +0200
@@ -39,14 +39,15 @@
             return {}
 
     def _is_postmaster_process(self):
+        postmaster_pid = int(self._postmaster_pid.get('pid', 0))
         try:
-            start_time = int(self._postmaster_pid.get('start_time', 0))
-            if start_time and abs(self.create_time() - start_time) > 3:
-                logger.info('Process %s is not postmaster, too much difference between PID file start time %s and '
-                            'process start time %s', self.pid, self.create_time(), start_time)
-                return False
-        except ValueError:
-            logger.warning('Garbage start time value in pid file: %r', self._postmaster_pid.get('start_time'))
+            self.send_signal(0)
+        except psutil.NoSuchProcess:
+            logger.warning("Could not send stop signal to PostgreSQL")
+            return False
+        except psutil.AccessDenied as e:
+            logger.warning("Could not send stop signal to PostgreSQL (error: {0})".format(e))
+            return False
 
         # Extra safety check. The process can't be ourselves, our parent or our direct child.
         if self.pid == os.getpid() or self.pid == os.getppid() or self.ppid() == os.getpid():