diff --git a/HACKING.rst b/HACKING.rst
index a2754da..b3b107e 100644
--- a/HACKING.rst
+++ b/HACKING.rst
@@ -9,3 +9,5 @@ masakari-monitors Specific Commandments
 - [M301] Ensure that the _() function is explicitly imported to ensure proper translations.
 - [M302] Validate that log messages are not translated.
 - [M303] Yield must always be followed by a space when yielding a value.
+- [M304] Check for usage of deprecated assertRaisesRegexp
+- [M305] LOG.warn is deprecated. Enforce use of LOG.warning.
diff --git a/masakarimonitors/hacking/checks.py b/masakarimonitors/hacking/checks.py
index 89a00d4..a2a4004 100644
--- a/masakarimonitors/hacking/checks.py
+++ b/masakarimonitors/hacking/checks.py
@@ -114,3 +114,18 @@ def assert_raisesRegexp(logical_line):
     if res:
         yield (0, "M304: assertRaisesRegex must be used instead "
                   "of assertRaisesRegexp")
+
+
+@core.flake8ext
+def no_log_warn(logical_line):
+    """Disallow 'LOG.warn('
+
+    LOG.warn() is deprecated and LOG.warning should be used instead.
+    https://docs.python.org/3/library/logging.html#logging.warning
+
+    N352
+    """
+
+    msg = ("M305: LOG.warn is deprecated, please use LOG.warning!")
+    if "LOG.warn(" in logical_line:
+        yield (0, msg)
diff --git a/masakarimonitors/introspectiveinstancemonitor/qemu_utils.py b/masakarimonitors/introspectiveinstancemonitor/qemu_utils.py
index d94a9b5..51ce281 100755
--- a/masakarimonitors/introspectiveinstancemonitor/qemu_utils.py
+++ b/masakarimonitors/introspectiveinstancemonitor/qemu_utils.py
@@ -271,8 +271,8 @@ class QemuGuestAgent(object):
                 self._getJournalObject(domain_uuid).processEvent('report')
                 self._getJournalObject(domain_uuid).setSentNotification(True)
             except Exception:
-                LOG.warn('Exception :' + domain_uuid +
-                    ' @ ' + get_function_name())
+                LOG.warning('Exception :' + domain_uuid +
+                            ' @ ' + get_function_name())
                 pass
 
     def _qemuAgentGuestPing(self, domain, timeout, flags=0):
@@ -405,10 +405,10 @@ class QemuGuestAgent(object):
                                 do_qemuAgentGuestPing(domain,
                                     ICONF.guest_monitoring_timeout)
                         except libvirt.libvirtError as le:
-                            LOG.warn(le)
+                            LOG.warning(le)
                             continue
         except Exception as e:
-            LOG.warn(e)
+            LOG.warning(e)
             pass
 
 
diff --git a/masakarimonitors/tests/unit/test_hacking.py b/masakarimonitors/tests/unit/test_hacking.py
index 129bec9..811d0b9 100644
--- a/masakarimonitors/tests/unit/test_hacking.py
+++ b/masakarimonitors/tests/unit/test_hacking.py
@@ -145,3 +145,15 @@ class HackingTestCase(testtools.TestCase):
                   yieldx_func(a, b)
                """
         self._assert_has_no_errors(code, checks.yield_followed_by_space)
+
+    def test_no_log_warn(self):
+        code = """
+                  LOG.warn("LOG.warn is deprecated")
+               """
+        errors = [(1, 0, 'M305')]
+        self._assert_has_errors(code, checks.no_log_warn,
+                                expected_errors=errors)
+        code = """
+                  LOG.warning("LOG.warn is deprecated")
+               """
+        self._assert_has_no_errors(code, checks.no_log_warn)
diff --git a/tox.ini b/tox.ini
index 0b33446..2cca0a2 100644
--- a/tox.ini
+++ b/tox.ini
@@ -115,6 +115,7 @@ extension =
     M302 = checks:no_translate_logs
     M303 = checks:yield_followed_by_space
     M304 = checks:assert_raisesRegexp
+    M305 = checks:no_log_warn
 paths = ./masakarimonitors/hacking
 
 [testenv:bindep]