diff --git a/HACKING.rst b/HACKING.rst
index 80d58701c64..48e4ed6b8f0 100644
--- a/HACKING.rst
+++ b/HACKING.rst
@@ -28,7 +28,6 @@ Neutron Specific Commandments
 - [N334] Use unittest2 uniformly across Neutron.
 - [N340] Check usage of <module>.i18n (and neutron.i18n)
 - [N341] Check usage of _ from python builtins
-- [N342] String interpolation should be delayed at logging calls.
 - [N343] Production code must not import from neutron.tests.*
 - [N344] Python 3: Do not use filter(lambda obj: test(obj), data). Replace it
   with [obj for obj in data if test(obj)].
diff --git a/neutron/hacking/checks.py b/neutron/hacking/checks.py
index a253a15c1a6..b83767af785 100644
--- a/neutron/hacking/checks.py
+++ b/neutron/hacking/checks.py
@@ -64,9 +64,6 @@ def _regex_for_level(level, hint):
     }
 
 
-log_string_interpolation = re.compile(r".*LOG\.(?:error|warn|warning|info"
-                                      r"|critical|exception|debug)"
-                                      r"\([^,]*%[^,]*[,)]")
 log_translation_hint = re.compile(
     '|'.join('(?:%s)' % _regex_for_level(level, hint)
              for level, hint in six.iteritems(_all_log_levels)))
@@ -364,28 +361,6 @@ def check_unittest_imports(logical_line):
         yield (0, msg)
 
 
-@flake8ext
-def check_delayed_string_interpolation(logical_line, filename, noqa):
-    """N342 String interpolation should be delayed at logging calls.
-
-    N342: LOG.debug('Example: %s' % 'bad')
-    Okay: LOG.debug('Example: %s', 'good')
-    """
-    msg = ("N342 String interpolation should be delayed to be "
-           "handled by the logging code, rather than being done "
-           "at the point of the logging call. "
-           "Use ',' instead of '%'.")
-
-    if noqa:
-        return
-
-    if 'neutron/tests/' in filename:
-        return
-
-    if log_string_interpolation.match(logical_line):
-        yield(0, msg)
-
-
 @flake8ext
 def check_no_imports_from_tests(logical_line, filename, noqa):
     """N343 Production code must not import from neutron.tests.*
@@ -432,6 +407,5 @@ def factory(register):
     register(check_oslo_i18n_wrapper)
     register(check_builtins_gettext)
     register(check_unittest_imports)
-    register(check_delayed_string_interpolation)
     register(check_no_imports_from_tests)
     register(check_python3_no_filter)
diff --git a/neutron/tests/unit/hacking/test_checks.py b/neutron/tests/unit/hacking/test_checks.py
index 536f58716c8..c891633b124 100644
--- a/neutron/tests/unit/hacking/test_checks.py
+++ b/neutron/tests/unit/hacking/test_checks.py
@@ -301,39 +301,6 @@ class HackingTestCase(base.BaseTestCase):
         self.assertLineFails(f, 'from unittest.TestSuite')
         self.assertLineFails(f, 'import unittest')
 
-    def test_check_delayed_string_interpolation(self):
-        dummy_noqa = CREATE_DUMMY_MATCH_OBJECT.search('a')
-
-        # In 'logical_line', Contents of strings replaced with
-        # "xxx" of same length.
-        fail_code1 = 'LOG.error(_LE("xxxxxxxxxxxxxxx") % value)'
-        fail_code2 = "LOG.warning(msg % 'xxxxx')"
-
-        self.assertEqual(
-            1, len(list(checks.check_delayed_string_interpolation(fail_code1,
-                                        "neutron/common/rpc.py", None))))
-        self.assertEqual(
-            1, len(list(checks.check_delayed_string_interpolation(fail_code2,
-                                        "neutron/common/rpc.py", None))))
-
-        pass_code1 = 'LOG.error(_LE("xxxxxxxxxxxxxxxxxx"), value)'
-        pass_code2 = "LOG.warning(msg, 'xxxxx')"
-        self.assertEqual(
-            0, len(list(checks.check_delayed_string_interpolation(pass_code1,
-                                        "neutron/common/rpc.py", None))))
-        self.assertEqual(
-            0, len(list(checks.check_delayed_string_interpolation(pass_code2,
-                                        "neutron/common/rpc.py", None))))
-        # check a file in neutron/tests
-        self.assertEqual(
-            0, len(list(checks.check_delayed_string_interpolation(fail_code1,
-                                        "neutron/tests/test_assert.py",
-                                        None))))
-        # check code including 'noqa'
-        self.assertEqual(
-            0, len(list(checks.check_delayed_string_interpolation(fail_code1,
-                                        "neutron/common/rpc.py", dummy_noqa))))
-
     def test_check_log_warn_deprecated(self):
         bad = "LOG.warn(_LW('i am zlatan!'))"
         self.assertEqual(
diff --git a/test-requirements.txt b/test-requirements.txt
index ef7410e754c..83d4eac97ae 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -1,7 +1,7 @@
 # The order of packages is significant, because pip processes them in the order
 # of appearance. Changing the order has an impact on the overall integration
 # process, which may cause wedges in the gate later.
-hacking<0.12,>=0.11.0 # Apache-2.0
+hacking<0.13,>=0.12.0 # Apache-2.0
 
 coverage>=4.0 # Apache-2.0
 fixtures>=3.0.0 # Apache-2.0/BSD
diff --git a/tox.ini b/tox.ini
index 0835f9af021..d3138031fe9 100644
--- a/tox.ini
+++ b/tox.ini
@@ -138,6 +138,8 @@ commands = sphinx-build -W -b html doc/source doc/build/html
 # H404 multi line docstring should start with a summary
 # H405 multi line docstring summary not separated with an empty line
 ignore = E125,E126,E128,E129,E265,H404,H405
+# H904: Delay string interpolations at logging calls
+enable-extensions=H904
 show-source = true
 exclude = ./.*,build,dist