diff --git a/lib/forms.py b/core/forms.py
similarity index 98%
rename from lib/forms.py
rename to core/forms.py
index ca6bd747c19677691660957187f3068917bfd59c..4ab3ac9ae685aecfb387f1a734cc96132d725108 100644
--- a/lib/forms.py
+++ b/core/forms.py
@@ -43,7 +43,7 @@ class NOCForm(forms.Form):
     Form wrapper returning NOCBoundField items
     """
 
-    class Media:
+    class Media(object):
         css = {"all": ["/ui/pkg/django-media/admin/css/forms.css"]}
 
     def __init__(self, *args, **kwargs):
diff --git a/lib/app/application.py b/lib/app/application.py
index 6671d8f723af137428bdd4dcb8ee2cce4286e166..f80841fe3261f1329931c2be0f0c45dff305f1f3 100644
--- a/lib/app/application.py
+++ b/lib/app/application.py
@@ -35,7 +35,7 @@ import six
 import jinja2
 
 # NOC modules
-from noc.lib.forms import NOCForm
+from noc.core.forms import NOCForm
 from noc import settings
 from noc.sa.interfaces.base import DictParameter
 from noc.core.cache.base import cache
@@ -104,8 +104,8 @@ class ApplicationBase(type):
     Application metaclass. Registers application class to site
     """
 
-    def __new__(cls, name, bases, attrs):
-        m = type.__new__(cls, name, bases, attrs)
+    def __new__(mcs, name, bases, attrs):
+        m = type.__new__(mcs, name, bases, attrs)
         for name in attrs:
             m.add_to_class(name, attrs[name])
         if "apps" in m.__module__:
diff --git a/services/web/apps/ip/tools/views.py b/services/web/apps/ip/tools/views.py
index b649615c8cf4869b5891ec63a79bde16285bd97c..65ff5d98f731b055f7966ac98feeee513c77a4ee 100644
--- a/services/web/apps/ip/tools/views.py
+++ b/services/web/apps/ip/tools/views.py
@@ -2,7 +2,7 @@
 # ---------------------------------------------------------------------
 # Tools
 # ---------------------------------------------------------------------
-# Copyright (C) 2007-2018 The NOC Project
+# Copyright (C) 2007-2019 The NOC Project
 # See LICENSE for details
 # ---------------------------------------------------------------------
 
@@ -20,7 +20,7 @@ from noc.core.ip import IP, IPv4
 from noc.ip.models.address import Address
 from noc.ip.models.prefix import Prefix
 from noc.ip.models.vrf import VRF
-from noc.lib.forms import NOCForm
+from noc.core.forms import NOCForm
 from noc.config import config
 from noc.core.translation import ugettext as _
 
diff --git a/services/web/apps/main/checkpoint/views.py b/services/web/apps/main/checkpoint/views.py
index 30853d98a9a992fae6e77733ecfb8b960fc04371..90ede1917b1ea02b7cb6f7f4386ab79d967cea10 100644
--- a/services/web/apps/main/checkpoint/views.py
+++ b/services/web/apps/main/checkpoint/views.py
@@ -2,7 +2,7 @@
 # ---------------------------------------------------------------------
 # Checkpoint manager
 # ---------------------------------------------------------------------
-# Copyright (C) 2007-2018 The NOC Project
+# Copyright (C) 2007-2019 The NOC Project
 # See LICENSE for details
 # ---------------------------------------------------------------------
 
@@ -14,7 +14,7 @@ from django import forms
 
 # NOC modules
 from noc.lib.app.application import Application, view, HasPerm
-from noc.lib.forms import NOCForm
+from noc.core.forms import NOCForm
 from noc.main.models.checkpoint import Checkpoint
 from noc.core.translation import ugettext as _
 
diff --git a/tests/test_forms.py b/tests/test_forms.py
new file mode 100644
index 0000000000000000000000000000000000000000..a796820b6502f3f83b87df8055fcabf9530a1f53
--- /dev/null
+++ b/tests/test_forms.py
@@ -0,0 +1,37 @@
+# -*- coding: utf-8 -*-
+# ----------------------------------------------------------------------
+# noc.core.forms unittests
+# ----------------------------------------------------------------------
+# Copyright (C) 2007-2019 The NOC Project
+# See LICENSE for details
+# ----------------------------------------------------------------------
+
+# Third-party modules
+import pytest
+from django import forms
+from django.core.wsgi import get_wsgi_application
+
+# NOC modules
+from noc.core.forms import NOCForm
+
+app = get_wsgi_application()
+
+
+class TestF(NOCForm):
+    charf = forms.CharField(required=True)
+    intf = forms.IntegerField(min_value=18)
+
+
+@pytest.mark.parametrize(
+    "charf, intf, expected",
+    [
+        ("field1", 18, True),
+        ("field2", 17, False),
+        ("field3", None, False),
+        ("", 18, False),
+        (None, 18, False),
+    ],
+)
+def test_f(charf, intf, expected):
+    f = TestF(data={"charf": charf, "intf": intf})
+    assert f.is_valid() is expected