diff --git a/src/systemd/journal.py b/src/systemd/journal.py
index 16729e9..da3404a 100644
--- a/src/systemd/journal.py
+++ b/src/systemd/journal.py
@@ -287,13 +287,7 @@ def seek_realtime(self, realtime):
         >>> j.seek_realtime(yesterday)
         """
         if isinstance(realtime, _datetime.datetime):
-            try:
-                realtime = realtime.astimezone()
-            except TypeError:
-                # With python2: Required argument 'tz' (pos 1) not found
-                pass
-
-            realtime = int(float(realtime.strftime("%s.%f")) * 1000000)
+            realtime = int(realtime.astimezone().timestamp() * 1000000)
         elif not isinstance(realtime, int):
             realtime = int(realtime * 1000000)
         return super(Reader, self).seek_realtime(realtime)
diff --git a/src/systemd/test/test_daemon.py b/src/systemd/test/test_daemon.py
index 6076f25..7355153 100644
--- a/src/systemd/test/test_daemon.py
+++ b/src/systemd/test/test_daemon.py
@@ -331,9 +331,7 @@ def test_notify_with_socket(tmpdir):
         sock.bind(path)
     except socket.error as e:
         pytest.xfail('failed to bind socket (%s)' % e)
-    # SO_PASSCRED is not defined in python2.7
-    SO_PASSCRED = getattr(socket, 'SO_PASSCRED', 16)
-    sock.setsockopt(socket.SOL_SOCKET, SO_PASSCRED, 1)
+    sock.setsockopt(socket.SOL_SOCKET, socket.SO_PASSCRED, 1)
     os.environ['NOTIFY_SOCKET'] = path
 
     assert notify('READY=1')
diff --git a/src/systemd/test/test_id128.py b/src/systemd/test/test_id128.py
index ffab469..ece098b 100644
--- a/src/systemd/test/test_id128.py
+++ b/src/systemd/test/test_id128.py
@@ -23,8 +23,7 @@ def test_randomize():
     assert u1 != u2
 
 def test_get_machine():
-    # yikes, python2 doesn't know ENOMEDIUM
-    with skip_oserror(errno.ENOENT, errno.ENOSYS, 123):
+    with skip_oserror(errno.ENOENT, errno.ENOSYS, errno.ENOMEDIUM):
         u1 = id128.get_machine()
 
     u2 = id128.get_machine()