diff --git a/stix2/custom.py b/stix2/custom.py
index 6d1abc5..387906b 100644
--- a/stix2/custom.py
+++ b/stix2/custom.py
@@ -8,34 +8,12 @@ from .parsing import (
     _register_marking, _register_object, _register_observable,
     _register_observable_extension,
 )
-from .utils import (
-    PREFIX_21_REGEX, TYPE_21_REGEX, TYPE_REGEX, get_class_hierarchy_names,
-)
+from .utils import PREFIX_21_REGEX, get_class_hierarchy_names
 
 
 def _custom_object_builder(cls, type, properties, version, base_class):
     class _CustomObject(cls, base_class):
 
-        if version == "2.0":
-            if not re.match(TYPE_REGEX, type):
-                raise ValueError(
-                    "Invalid type name '%s': must only contain the "
-                    "characters a-z (lowercase ASCII), 0-9, and hyphen (-)." %
-                    type,
-                )
-        else:  # 2.1+
-            if not re.match(TYPE_21_REGEX, type):
-                raise ValueError(
-                    "Invalid type name '%s': must only contain the "
-                    "characters a-z (lowercase ASCII), 0-9, and hyphen (-) "
-                    "and must begin with an a-z character" % type,
-                )
-
-        if len(type) < 3 or len(type) > 250:
-            raise ValueError(
-                "Invalid type name '%s': must be between 3 and 250 characters." % type,
-            )
-
         if not properties or not isinstance(properties, list):
             raise ValueError("Must supply a list, containing tuples. For example, [('property1', IntegerProperty())]")
 
@@ -79,24 +57,6 @@ def _custom_observable_builder(cls, type, properties, version, base_class, id_co
 
     class _CustomObservable(cls, base_class):
 
-        if version == "2.0":
-            if not re.match(TYPE_REGEX, type):
-                raise ValueError(
-                    "Invalid observable type name '%s': must only contain the "
-                    "characters a-z (lowercase ASCII), 0-9, and hyphen (-)." %
-                    type,
-                )
-        else:  # 2.1+
-            if not re.match(TYPE_21_REGEX, type):
-                raise ValueError(
-                    "Invalid observable type name '%s': must only contain the "
-                    "characters a-z (lowercase ASCII), 0-9, and hyphen (-) "
-                    "and must begin with an a-z character" % type,
-                )
-
-        if len(type) < 3 or len(type) > 250:
-            raise ValueError("Invalid observable type name '%s': must be between 3 and 250 characters." % type)
-
         if not properties or not isinstance(properties, list):
             raise ValueError("Must supply a list, containing tuples. For example, [('property1', IntegerProperty())]")
 
diff --git a/stix2/parsing.py b/stix2/parsing.py
index 7dedc15..f355f41 100644
--- a/stix2/parsing.py
+++ b/stix2/parsing.py
@@ -7,11 +7,9 @@ import re
 
 import stix2
 
-from .base import _Observable
+from .base import _DomainObject, _Observable
 from .exceptions import ParseError
-from .utils import (
-    EXT_21_REGEX, PREFIX_21_REGEX, TYPE_21_REGEX, TYPE_REGEX, _get_dict,
-)
+from .utils import PREFIX_21_REGEX, _get_dict
 
 STIX2_OBJ_MAPS = {}
 
@@ -204,6 +202,14 @@ def _register_object(new_type, version=None):
 
     """
 
+    if not issubclass(new_type, _DomainObject):
+        raise ValueError(
+            "'%s' must be created with the @CustomObject decorator." %
+            new_type.__name__,
+        )
+
+    new_type._properties['type'].clean(new_type._type)
+
     if version:
         v = 'v' + version.replace('.', '')
     else:
@@ -224,28 +230,6 @@ def _register_marking(new_marking, version=None):
 
     """
 
-    type = new_marking._type
-
-    if version == "2.0":
-        if not re.match(TYPE_REGEX, type):
-            raise ValueError(
-                "Invalid marking type name '%s': must only contain the "
-                "characters a-z (lowercase ASCII), 0-9, and hyphen (-)." %
-                type,
-            )
-    else:  # 2.1+
-        if not re.match(TYPE_21_REGEX, type):
-            raise ValueError(
-                "Invalid marking type name '%s': must only contain the "
-                "characters a-z (lowercase ASCII), 0-9, and hyphen (-) "
-                "and must begin with an a-z character" % type,
-            )
-
-    if len(type) < 3 or len(type) > 250:
-        raise ValueError(
-            "Invalid marking type name '%s': must be between 3 and 250 characters." % type,
-        )
-
     properties = new_marking._properties
 
     if version == "2.1":
@@ -273,6 +257,8 @@ def _register_observable(new_observable, version=None):
 
     """
 
+    new_observable._properties['type'].clean(new_observable._type)
+
     if version:
         v = 'v' + version.replace('.', '')
     else:
@@ -304,26 +290,12 @@ def _register_observable_extension(
     if not issubclass(obs_class, _Observable):
         raise ValueError("'observable' must be a valid Observable class!")
 
-    if version == "2.0":
-        if not re.match(TYPE_REGEX, ext_type):
-            raise ValueError(
-                "Invalid extension type name '%s': must only contain the "
-                "characters a-z (lowercase ASCII), 0-9, and hyphen (-)." %
-                ext_type,
-            )
-    else:  # 2.1+
-        if not re.match(EXT_21_REGEX, ext_type):
-            raise ValueError(
-                "Invalid extension type name '%s': must only contain the "
-                "characters a-z (lowercase ASCII), 0-9, hyphen (-), "
-                "must begin with an a-z character"
-                "and end with '-ext'." % ext_type,
-            )
-
-    if len(ext_type) < 3 or len(ext_type) > 250:
+    temp_prop = stix2.properties.TypeProperty(ext_type, spec_version=version)
+    temp_prop.clean(ext_type)
+    if not ext_type.endswith('-ext'):
         raise ValueError(
-            "Invalid extension type name '%s': must be between 3 and 250"
-            " characters." % ext_type,
+            "Invalid extension type name '%s': must end with '-ext'." %
+            ext_type,
         )
 
     if not new_extension._properties:
diff --git a/stix2/properties.py b/stix2/properties.py
index be66533..4ccfa89 100644
--- a/stix2/properties.py
+++ b/stix2/properties.py
@@ -17,7 +17,10 @@ from .exceptions import (
     MutuallyExclusivePropertiesError,
 )
 from .parsing import STIX2_OBJ_MAPS, parse, parse_observable
-from .utils import _get_dict, get_class_hierarchy_names, parse_into_datetime
+from .utils import (
+    TYPE_21_REGEX, TYPE_REGEX, _get_dict, get_class_hierarchy_names,
+    parse_into_datetime,
+)
 
 try:
     from collections.abc import Mapping
@@ -232,9 +235,33 @@ class StringProperty(Property):
 
 class TypeProperty(Property):
 
-    def __init__(self, type):
+    def __init__(self, type, spec_version=stix2.DEFAULT_VERSION):
+        self.spec_version = spec_version
         super(TypeProperty, self).__init__(fixed=type)
 
+    def clean(self, value):
+        if self.spec_version == "2.0":
+            if not re.match(TYPE_REGEX, type):
+                raise ValueError(
+                    "Invalid type name '%s': must only contain the "
+                    "characters a-z (lowercase ASCII), 0-9, and hyphen (-)." %
+                    type,
+                )
+        else:  # 2.1+
+            if not re.match(TYPE_21_REGEX, type):
+                raise ValueError(
+                    "Invalid type name '%s': must only contain the "
+                    "characters a-z (lowercase ASCII), 0-9, and hyphen (-) "
+                    "and must begin with an a-z character" % type,
+                )
+
+        if len(type) < 3 or len(type) > 250:
+            raise ValueError(
+                "Invalid type name '%s': must be between 3 and 250 characters." % type,
+            )
+
+        return value
+
 
 class IDProperty(Property):
 
diff --git a/stix2/test/v21/test_custom.py b/stix2/test/v21/test_custom.py
index a9969b8..2183d4f 100644
--- a/stix2/test/v21/test_custom.py
+++ b/stix2/test/v21/test_custom.py
@@ -1186,9 +1186,9 @@ def test_register_custom_object():
     class CustomObject2(object):
         _type = 'awesome-object'
 
-    stix2.parsing._register_object(CustomObject2, version="2.1")
-    # Note that we will always check against newest OBJ_MAP.
-    assert (CustomObject2._type, CustomObject2) in stix2.v21.OBJ_MAP.items()
+    with pytest.raises(ValueError) as excinfo:
+        stix2.parsing._register_object(CustomObject2, version="2.1")
+    assert '@CustomObject decorator' in str(excinfo)
 
 
 def test_extension_property_location():
diff --git a/stix2/utils.py b/stix2/utils.py
index 69489d9..7acf523 100644
--- a/stix2/utils.py
+++ b/stix2/utils.py
@@ -28,7 +28,6 @@ STIX_UNMOD_PROPERTIES = ['created', 'created_by_ref', 'id', 'type']
 
 TYPE_REGEX = re.compile(r'^\-?[a-z0-9]+(-[a-z0-9]+)*\-?$')
 TYPE_21_REGEX = re.compile(r'^([a-z][a-z0-9]*)+(-[a-z0-9]+)*\-?$')
-EXT_21_REGEX = re.compile(r'^([a-z][a-z0-9]*)+(-[a-z0-9]+)*\-ext$')
 PREFIX_21_REGEX = re.compile(r'^[a-z].*')
 
 
diff --git a/stix2/v20/bundle.py b/stix2/v20/bundle.py
index b811a79..25b948d 100644
--- a/stix2/v20/bundle.py
+++ b/stix2/v20/bundle.py
@@ -15,7 +15,7 @@ class Bundle(_STIXBase20):
 
     _type = 'bundle'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.0')),
         ('id', IDProperty(_type, spec_version='2.0')),
         # Not technically correct: STIX 2.0 spec doesn't say spec_version must
         # have this value, but it's all we support for now.
diff --git a/stix2/v20/common.py b/stix2/v20/common.py
index 55f2c3e..a92f81d 100644
--- a/stix2/v20/common.py
+++ b/stix2/v20/common.py
@@ -120,7 +120,7 @@ class MarkingDefinition(_STIXBase20, _MarkingsMixin):
 
     _type = 'marking-definition'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.0')),
         ('id', IDProperty(_type, spec_version='2.0')),
         ('created_by_ref', ReferenceProperty(valid_types='identity', spec_version='2.0')),
         ('created', TimestampProperty(default=lambda: NOW)),
diff --git a/stix2/v20/observables.py b/stix2/v20/observables.py
index eb9bfde..3491c47 100644
--- a/stix2/v20/observables.py
+++ b/stix2/v20/observables.py
@@ -26,7 +26,7 @@ class Artifact(_Observable):
 
     _type = 'artifact'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.0')),
         ('mime_type', StringProperty()),
         ('payload_bin', BinaryProperty()),
         ('url', StringProperty()),
@@ -47,7 +47,7 @@ class AutonomousSystem(_Observable):
 
     _type = 'autonomous-system'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.0')),
         ('number', IntegerProperty(required=True)),
         ('name', StringProperty()),
         ('rir', StringProperty()),
@@ -62,7 +62,7 @@ class Directory(_Observable):
 
     _type = 'directory'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.0')),
         ('path', StringProperty(required=True)),
         ('path_enc', StringProperty()),
         # these are not the created/modified timestamps of the object itself
@@ -81,7 +81,7 @@ class DomainName(_Observable):
 
     _type = 'domain-name'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.0')),
         ('value', StringProperty(required=True)),
         ('resolves_to_refs', ListProperty(ObjectReferenceProperty(valid_types=['ipv4-addr', 'ipv6-addr', 'domain-name']))),
         ('extensions', ExtensionsProperty(spec_version="2.0", enclosing_type=_type)),
@@ -95,7 +95,7 @@ class EmailAddress(_Observable):
 
     _type = 'email-addr'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.0')),
         ('value', StringProperty(required=True)),
         ('display_name', StringProperty()),
         ('belongs_to_ref', ObjectReferenceProperty(valid_types='user-account')),
@@ -127,7 +127,7 @@ class EmailMessage(_Observable):
 
     _type = 'email-message'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.0')),
         ('is_multipart', BooleanProperty(required=True)),
         ('date', TimestampProperty()),
         ('content_type', StringProperty()),
@@ -306,7 +306,7 @@ class File(_Observable):
 
     _type = 'file'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.0')),
         ('hashes', HashesProperty()),
         ('size', IntegerProperty()),
         ('name', StringProperty()),
@@ -339,7 +339,7 @@ class IPv4Address(_Observable):
 
     _type = 'ipv4-addr'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.0')),
         ('value', StringProperty(required=True)),
         ('resolves_to_refs', ListProperty(ObjectReferenceProperty(valid_types='mac-addr'))),
         ('belongs_to_refs', ListProperty(ObjectReferenceProperty(valid_types='autonomous-system'))),
@@ -354,7 +354,7 @@ class IPv6Address(_Observable):
 
     _type = 'ipv6-addr'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.0')),
         ('value', StringProperty(required=True)),
         ('resolves_to_refs', ListProperty(ObjectReferenceProperty(valid_types='mac-addr'))),
         ('belongs_to_refs', ListProperty(ObjectReferenceProperty(valid_types='autonomous-system'))),
@@ -369,7 +369,7 @@ class MACAddress(_Observable):
 
     _type = 'mac-addr'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.0')),
         ('value', StringProperty(required=True)),
         ('extensions', ExtensionsProperty(spec_version="2.0", enclosing_type=_type)),
     ])
@@ -382,7 +382,7 @@ class Mutex(_Observable):
 
     _type = 'mutex'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.0')),
         ('name', StringProperty(required=True)),
         ('extensions', ExtensionsProperty(spec_version="2.0", enclosing_type=_type)),
     ])
@@ -483,7 +483,7 @@ class NetworkTraffic(_Observable):
 
     _type = 'network-traffic'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.0')),
         ('start', TimestampProperty()),
         ('end', TimestampProperty()),
         ('is_active', BooleanProperty()),
@@ -575,7 +575,7 @@ class Process(_Observable):
 
     _type = 'process'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.0')),
         ('is_hidden', BooleanProperty()),
         ('pid', IntegerProperty()),
         ('name', StringProperty()),
@@ -615,7 +615,7 @@ class Software(_Observable):
 
     _type = 'software'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.0')),
         ('name', StringProperty(required=True)),
         ('cpe', StringProperty()),
         ('languages', ListProperty(StringProperty)),
@@ -632,7 +632,7 @@ class URL(_Observable):
 
     _type = 'url'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.0')),
         ('value', StringProperty(required=True)),
         ('extensions', ExtensionsProperty(spec_version="2.0", enclosing_type=_type)),
     ])
@@ -659,7 +659,7 @@ class UserAccount(_Observable):
 
     _type = 'user-account'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.0')),
         ('user_id', StringProperty(required=True)),
         ('account_login', StringProperty()),
         ('account_type', StringProperty()),   # open vocab
@@ -713,7 +713,7 @@ class WindowsRegistryKey(_Observable):
 
     _type = 'windows-registry-key'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.0')),
         ('key', StringProperty(required=True)),
         ('values', ListProperty(EmbeddedObjectProperty(type=WindowsRegistryValueType))),
         # this is not the modified timestamps of the object itself
@@ -757,7 +757,7 @@ class X509Certificate(_Observable):
 
     _type = 'x509-certificate'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.0')),
         ('is_self_signed', BooleanProperty()),
         ('hashes', HashesProperty()),
         ('version', StringProperty()),
@@ -791,7 +791,7 @@ def CustomObservable(type='x-custom-observable', properties=None):
     """
     def wrapper(cls):
         _properties = list(itertools.chain.from_iterable([
-            [('type', TypeProperty(type))],
+            [('type', TypeProperty(type, spec_version='2.0'))],
             properties,
             [('extensions', ExtensionsProperty(spec_version="2.0", enclosing_type=type))],
         ]))
diff --git a/stix2/v20/sdo.py b/stix2/v20/sdo.py
index cb5ba04..8cbd94b 100644
--- a/stix2/v20/sdo.py
+++ b/stix2/v20/sdo.py
@@ -24,7 +24,7 @@ class AttackPattern(_DomainObject):
 
     _type = 'attack-pattern'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.0')),
         ('id', IDProperty(_type, spec_version='2.0')),
         ('created_by_ref', ReferenceProperty(valid_types='identity', spec_version='2.0')),
         ('created', TimestampProperty(default=lambda: NOW, precision='millisecond')),
@@ -47,7 +47,7 @@ class Campaign(_DomainObject):
 
     _type = 'campaign'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.0')),
         ('id', IDProperty(_type, spec_version='2.0')),
         ('created_by_ref', ReferenceProperty(valid_types='identity', spec_version='2.0')),
         ('created', TimestampProperty(default=lambda: NOW, precision='millisecond')),
@@ -73,7 +73,7 @@ class CourseOfAction(_DomainObject):
 
     _type = 'course-of-action'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.0')),
         ('id', IDProperty(_type, spec_version='2.0')),
         ('created_by_ref', ReferenceProperty(valid_types='identity', spec_version='2.0')),
         ('created', TimestampProperty(default=lambda: NOW, precision='millisecond')),
@@ -95,7 +95,7 @@ class Identity(_DomainObject):
 
     _type = 'identity'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.0')),
         ('id', IDProperty(_type, spec_version='2.0')),
         ('created_by_ref', ReferenceProperty(valid_types='identity', spec_version='2.0')),
         ('created', TimestampProperty(default=lambda: NOW, precision='millisecond')),
@@ -120,7 +120,7 @@ class Indicator(_DomainObject):
 
     _type = 'indicator'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.0')),
         ('id', IDProperty(_type, spec_version='2.0')),
         ('created_by_ref', ReferenceProperty(valid_types='identity', spec_version='2.0')),
         ('created', TimestampProperty(default=lambda: NOW, precision='millisecond')),
@@ -151,7 +151,7 @@ class IntrusionSet(_DomainObject):
 
     _type = 'intrusion-set'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.0')),
         ('id', IDProperty(_type, spec_version='2.0')),
         ('created_by_ref', ReferenceProperty(valid_types='identity', spec_version='2.0')),
         ('created', TimestampProperty(default=lambda: NOW, precision='millisecond')),
@@ -180,7 +180,7 @@ class Malware(_DomainObject):
 
     _type = 'malware'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.0')),
         ('id', IDProperty(_type, spec_version='2.0')),
         ('created_by_ref', ReferenceProperty(valid_types='identity', spec_version='2.0')),
         ('created', TimestampProperty(default=lambda: NOW, precision='millisecond')),
@@ -203,7 +203,7 @@ class ObservedData(_DomainObject):
 
     _type = 'observed-data'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.0')),
         ('id', IDProperty(_type, spec_version='2.0')),
         ('created_by_ref', ReferenceProperty(valid_types='identity', spec_version='2.0')),
         ('created', TimestampProperty(default=lambda: NOW, precision='millisecond')),
@@ -233,7 +233,7 @@ class Report(_DomainObject):
 
     _type = 'report'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.0')),
         ('id', IDProperty(_type, spec_version='2.0')),
         ('created_by_ref', ReferenceProperty(valid_types='identity', spec_version='2.0')),
         ('created', TimestampProperty(default=lambda: NOW, precision='millisecond')),
@@ -257,7 +257,7 @@ class ThreatActor(_DomainObject):
 
     _type = 'threat-actor'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.0')),
         ('id', IDProperty(_type, spec_version='2.0')),
         ('created_by_ref', ReferenceProperty(valid_types='identity', spec_version='2.0')),
         ('created', TimestampProperty(default=lambda: NOW, precision='millisecond')),
@@ -287,7 +287,7 @@ class Tool(_DomainObject):
 
     _type = 'tool'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.0')),
         ('id', IDProperty(_type, spec_version='2.0')),
         ('created_by_ref', ReferenceProperty(valid_types='identity', spec_version='2.0')),
         ('created', TimestampProperty(default=lambda: NOW, precision='millisecond')),
@@ -311,7 +311,7 @@ class Vulnerability(_DomainObject):
 
     _type = 'vulnerability'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.0')),
         ('id', IDProperty(_type, spec_version='2.0')),
         ('created_by_ref', ReferenceProperty(valid_types='identity', spec_version='2.0')),
         ('created', TimestampProperty(default=lambda: NOW, precision='millisecond')),
@@ -358,7 +358,7 @@ def CustomObject(type='x-custom-type', properties=None):
     def wrapper(cls):
         _properties = list(itertools.chain.from_iterable([
             [
-                ('type', TypeProperty(type)),
+                ('type', TypeProperty(type, spec_version='2.0')),
                 ('id', IDProperty(type, spec_version='2.0')),
                 ('created_by_ref', ReferenceProperty(valid_types='identity', spec_version='2.0')),
                 ('created', TimestampProperty(default=lambda: NOW, precision='millisecond')),
diff --git a/stix2/v20/sro.py b/stix2/v20/sro.py
index b7d1ad3..1372a5e 100644
--- a/stix2/v20/sro.py
+++ b/stix2/v20/sro.py
@@ -20,7 +20,7 @@ class Relationship(_RelationshipObject):
 
     _type = 'relationship'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.0')),
         ('id', IDProperty(_type, spec_version='2.0')),
         ('created_by_ref', ReferenceProperty(valid_types='identity', spec_version='2.0')),
         ('created', TimestampProperty(default=lambda: NOW, precision='millisecond')),
@@ -59,7 +59,7 @@ class Sighting(_RelationshipObject):
 
     _type = 'sighting'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.0')),
         ('id', IDProperty(_type, spec_version='2.0')),
         ('created_by_ref', ReferenceProperty(valid_types='identity', spec_version='2.0')),
         ('created', TimestampProperty(default=lambda: NOW, precision='millisecond')),
diff --git a/stix2/v21/bundle.py b/stix2/v21/bundle.py
index ca60fe0..1b8c652 100644
--- a/stix2/v21/bundle.py
+++ b/stix2/v21/bundle.py
@@ -16,7 +16,7 @@ class Bundle(_STIXBase21):
 
     _type = 'bundle'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.1')),
         ('id', IDProperty(_type, spec_version='2.1')),
         ('objects', ListProperty(STIXObjectProperty(spec_version='2.1'))),
     ])
diff --git a/stix2/v21/common.py b/stix2/v21/common.py
index 4254767..115bdb5 100644
--- a/stix2/v21/common.py
+++ b/stix2/v21/common.py
@@ -87,7 +87,7 @@ class LanguageContent(_STIXBase21):
 
     _type = 'language-content'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.1')),
         ('spec_version', StringProperty(fixed='2.1')),
         ('id', IDProperty(_type, spec_version='2.1')),
         ('created_by_ref', ReferenceProperty(valid_types='identity', spec_version='2.1')),
@@ -158,7 +158,7 @@ class MarkingDefinition(_STIXBase21, _MarkingsMixin):
 
     _type = 'marking-definition'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.1')),
         ('spec_version', StringProperty(fixed='2.1')),
         ('id', IDProperty(_type)),
         ('created_by_ref', ReferenceProperty(valid_types='identity', spec_version='2.1')),
diff --git a/stix2/v21/observables.py b/stix2/v21/observables.py
index e71e445..275bbbe 100644
--- a/stix2/v21/observables.py
+++ b/stix2/v21/observables.py
@@ -29,7 +29,7 @@ class Artifact(_Observable):
 
     _type = 'artifact'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.1')),
         ('id', IDProperty(_type, spec_version='2.1')),
         ('mime_type', StringProperty()),
         ('payload_bin', BinaryProperty()),
@@ -59,7 +59,7 @@ class AutonomousSystem(_Observable):
 
     _type = 'autonomous-system'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.1')),
         ('id', IDProperty(_type, spec_version='2.1')),
         ('number', IntegerProperty(required=True)),
         ('name', StringProperty()),
@@ -81,7 +81,7 @@ class Directory(_Observable):
 
     _type = 'directory'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.1')),
         ('id', IDProperty(_type, spec_version='2.1')),
         ('path', StringProperty(required=True)),
         ('path_enc', StringProperty()),
@@ -107,7 +107,7 @@ class DomainName(_Observable):
 
     _type = 'domain-name'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.1')),
         ('id', IDProperty(_type, spec_version='2.1')),
         ('value', StringProperty(required=True)),
         ('resolves_to_refs', ListProperty(ReferenceProperty(valid_types=['ipv4-addr', 'ipv6-addr', 'domain-name'], spec_version='2.1'))),
@@ -128,7 +128,7 @@ class EmailAddress(_Observable):
 
     _type = 'email-addr'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.1')),
         ('id', IDProperty(_type, spec_version='2.1')),
         ('value', StringProperty(required=True)),
         ('display_name', StringProperty()),
@@ -168,7 +168,7 @@ class EmailMessage(_Observable):
 
     _type = 'email-message'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.1')),
         ('id', IDProperty(_type, spec_version='2.1')),
         ('is_multipart', BooleanProperty(required=True)),
         ('date', TimestampProperty()),
@@ -361,7 +361,7 @@ class File(_Observable):
 
     _type = 'file'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.1')),
         ('id', IDProperty(_type, spec_version='2.1')),
         ('hashes', HashesProperty(spec_version='2.1')),
         ('size', IntegerProperty(min=0)),
@@ -397,7 +397,7 @@ class IPv4Address(_Observable):
 
     _type = 'ipv4-addr'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.1')),
         ('id', IDProperty(_type, spec_version='2.1')),
         ('value', StringProperty(required=True)),
         ('resolves_to_refs', ListProperty(ReferenceProperty(valid_types='mac-addr', spec_version='2.1'))),
@@ -419,7 +419,7 @@ class IPv6Address(_Observable):
 
     _type = 'ipv6-addr'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.1')),
         ('id', IDProperty(_type, spec_version='2.1')),
         ('value', StringProperty(required=True)),
         ('resolves_to_refs', ListProperty(ReferenceProperty(valid_types='mac-addr', spec_version='2.1'))),
@@ -441,7 +441,7 @@ class MACAddress(_Observable):
 
     _type = 'mac-addr'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.1')),
         ('id', IDProperty(_type, spec_version='2.1')),
         ('value', StringProperty(required=True)),
         ('extensions', ExtensionsProperty(spec_version='2.1', enclosing_type=_type)),
@@ -461,7 +461,7 @@ class Mutex(_Observable):
 
     _type = 'mutex'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.1')),
         ('id', IDProperty(_type, spec_version='2.1')),
         ('name', StringProperty(required=True)),
         ('extensions', ExtensionsProperty(spec_version='2.1', enclosing_type=_type)),
@@ -586,7 +586,7 @@ class NetworkTraffic(_Observable):
 
     _type = 'network-traffic'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.1')),
         ('id', IDProperty(_type, spec_version='2.1')),
         ('start', TimestampProperty()),
         ('end', TimestampProperty()),
@@ -711,7 +711,7 @@ class Process(_Observable):
 
     _type = 'process'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.1')),
         ('id', IDProperty(_type, spec_version='2.1')),
         ('is_hidden', BooleanProperty()),
         ('pid', IntegerProperty()),
@@ -756,7 +756,7 @@ class Software(_Observable):
 
     _type = 'software'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.1')),
         ('id', IDProperty(_type, spec_version='2.1')),
         ('name', StringProperty(required=True)),
         ('cpe', StringProperty()),
@@ -781,7 +781,7 @@ class URL(_Observable):
 
     _type = 'url'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.1')),
         ('id', IDProperty(_type, spec_version='2.1')),
         ('value', StringProperty(required=True)),
         ('extensions', ExtensionsProperty(spec_version='2.1', enclosing_type=_type)),
@@ -816,7 +816,7 @@ class UserAccount(_Observable):
 
     _type = 'user-account'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.1')),
         ('id', IDProperty(_type, spec_version='2.1')),
         ('user_id', StringProperty()),
         ('credential', StringProperty()),
@@ -879,7 +879,7 @@ class WindowsRegistryKey(_Observable):
 
     _type = 'windows-registry-key'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.1')),
         ('id', IDProperty(_type, spec_version='2.1')),
         ('key', StringProperty()),
         ('values', ListProperty(EmbeddedObjectProperty(type=WindowsRegistryValueType))),
@@ -931,7 +931,7 @@ class X509Certificate(_Observable):
 
     _type = 'x509-certificate'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.1')),
         ('id', IDProperty(_type, spec_version='2.1')),
         ('is_self_signed', BooleanProperty()),
         ('hashes', HashesProperty(spec_version='2.1')),
@@ -983,7 +983,7 @@ def CustomObservable(type='x-custom-observable', properties=None, id_contrib_pro
     """
     def wrapper(cls):
         _properties = list(itertools.chain.from_iterable([
-            [('type', TypeProperty(type))],
+            [('type', TypeProperty(type, spec_version='2.1'))],
             [('id', IDProperty(type, spec_version='2.1'))],
             properties,
             [('extensions', ExtensionsProperty(spec_version='2.1', enclosing_type=type))],
diff --git a/stix2/v21/sdo.py b/stix2/v21/sdo.py
index 1e9633e..396b030 100644
--- a/stix2/v21/sdo.py
+++ b/stix2/v21/sdo.py
@@ -29,7 +29,7 @@ class AttackPattern(_DomainObject):
 
     _type = 'attack-pattern'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.1')),
         ('spec_version', StringProperty(fixed='2.1')),
         ('id', IDProperty(_type, spec_version='2.1')),
         ('created_by_ref', ReferenceProperty(valid_types='identity', spec_version='2.1')),
@@ -57,7 +57,7 @@ class Campaign(_DomainObject):
 
     _type = 'campaign'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.1')),
         ('spec_version', StringProperty(fixed='2.1')),
         ('id', IDProperty(_type, spec_version='2.1')),
         ('created_by_ref', ReferenceProperty(valid_types='identity', spec_version='2.1')),
@@ -97,7 +97,7 @@ class CourseOfAction(_DomainObject):
 
     _type = 'course-of-action'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.1')),
         ('spec_version', StringProperty(fixed='2.1')),
         ('id', IDProperty(_type, spec_version='2.1')),
         ('created_by_ref', ReferenceProperty(valid_types='identity', spec_version='2.1')),
@@ -123,7 +123,7 @@ class Grouping(_DomainObject):
 
     _type = 'grouping'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.1')),
         ('spec_version', StringProperty(fixed='2.1')),
         ('id', IDProperty(_type, spec_version='2.1')),
         ('created', TimestampProperty(default=lambda: NOW, precision='millisecond')),
@@ -151,7 +151,7 @@ class Identity(_DomainObject):
 
     _type = 'identity'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.1')),
         ('spec_version', StringProperty(fixed='2.1')),
         ('id', IDProperty(_type, spec_version='2.1')),
         ('created_by_ref', ReferenceProperty(valid_types='identity', spec_version='2.1')),
@@ -181,7 +181,7 @@ class Indicator(_DomainObject):
 
     _type = 'indicator'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.1')),
         ('spec_version', StringProperty(fixed='2.1')),
         ('id', IDProperty(_type, spec_version='2.1')),
         ('created_by_ref', ReferenceProperty(valid_types='identity', spec_version='2.1')),
@@ -241,7 +241,7 @@ class Infrastructure(_DomainObject):
 
     _type = 'infrastructure'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.1')),
         ('spec_version', StringProperty(fixed='2.1')),
         ('id', IDProperty(_type, spec_version='2.1')),
         ('created_by_ref', ReferenceProperty(valid_types='identity', spec_version='2.1')),
@@ -282,7 +282,7 @@ class IntrusionSet(_DomainObject):
 
     _type = 'intrusion-set'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.1')),
         ('spec_version', StringProperty(fixed='2.1')),
         ('id', IDProperty(_type, spec_version='2.1')),
         ('created_by_ref', ReferenceProperty(valid_types='identity', spec_version='2.1')),
@@ -325,7 +325,7 @@ class Location(_DomainObject):
 
     _type = 'location'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.1')),
         ('spec_version', StringProperty(fixed='2.1')),
         ('id', IDProperty(_type, spec_version='2.1')),
         ('created_by_ref', ReferenceProperty(valid_types='identity', spec_version='2.1')),
@@ -433,7 +433,7 @@ class Malware(_DomainObject):
 
     _type = 'malware'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.1')),
         ('spec_version', StringProperty(fixed='2.1')),
         ('id', IDProperty(_type, spec_version='2.1')),
         ('created_by_ref', ReferenceProperty(valid_types='identity', spec_version='2.1')),
@@ -486,7 +486,7 @@ class MalwareAnalysis(_DomainObject):
 
     _type = 'malware-analysis'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.1')),
         ('spec_version', StringProperty(fixed='2.1')),
         ('id', IDProperty(_type, spec_version='2.1')),
         ('created', TimestampProperty(default=lambda: NOW, precision='millisecond')),
@@ -531,7 +531,7 @@ class Note(_DomainObject):
 
     _type = 'note'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.1')),
         ('spec_version', StringProperty(fixed='2.1')),
         ('id', IDProperty(_type, spec_version='2.1')),
         ('created_by_ref', ReferenceProperty(valid_types='identity', spec_version='2.1')),
@@ -559,7 +559,7 @@ class ObservedData(_DomainObject):
 
     _type = 'observed-data'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.1')),
         ('spec_version', StringProperty(fixed='2.1')),
         ('id', IDProperty(_type, spec_version='2.1')),
         ('created_by_ref', ReferenceProperty(valid_types='identity', spec_version='2.1')),
@@ -615,7 +615,7 @@ class Opinion(_DomainObject):
 
     _type = 'opinion'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.1')),
         ('spec_version', StringProperty(fixed='2.1')),
         ('id', IDProperty(_type, spec_version='2.1')),
         ('created_by_ref', ReferenceProperty(valid_types='identity', spec_version='2.1')),
@@ -653,7 +653,7 @@ class Report(_DomainObject):
 
     _type = 'report'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.1')),
         ('spec_version', StringProperty(fixed='2.1')),
         ('id', IDProperty(_type, spec_version='2.1')),
         ('created_by_ref', ReferenceProperty(valid_types='identity', spec_version='2.1')),
@@ -682,7 +682,7 @@ class ThreatActor(_DomainObject):
 
     _type = 'threat-actor'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.1')),
         ('spec_version', StringProperty(fixed='2.1')),
         ('id', IDProperty(_type, spec_version='2.1')),
         ('created_by_ref', ReferenceProperty(valid_types='identity', spec_version='2.1')),
@@ -729,7 +729,7 @@ class Tool(_DomainObject):
 
     _type = 'tool'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.1')),
         ('spec_version', StringProperty(fixed='2.1')),
         ('id', IDProperty(_type, spec_version='2.1')),
         ('created_by_ref', ReferenceProperty(valid_types='identity', spec_version='2.1')),
@@ -759,7 +759,7 @@ class Vulnerability(_DomainObject):
 
     _type = 'vulnerability'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.1')),
         ('spec_version', StringProperty(fixed='2.1')),
         ('id', IDProperty(_type, spec_version='2.1')),
         ('created_by_ref', ReferenceProperty(valid_types='identity', spec_version='2.1')),
@@ -809,7 +809,7 @@ def CustomObject(type='x-custom-type', properties=None):
     def wrapper(cls):
         _properties = list(itertools.chain.from_iterable([
             [
-                ('type', TypeProperty(type)),
+                ('type', TypeProperty(type, spec_version='2.1')),
                 ('spec_version', StringProperty(fixed='2.1')),
                 ('id', IDProperty(type, spec_version='2.1')),
                 ('created_by_ref', ReferenceProperty(valid_types='identity', spec_version='2.1')),
diff --git a/stix2/v21/sro.py b/stix2/v21/sro.py
index 3ffdd77..9f85004 100644
--- a/stix2/v21/sro.py
+++ b/stix2/v21/sro.py
@@ -21,7 +21,7 @@ class Relationship(_RelationshipObject):
 
     _type = 'relationship'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.1')),
         ('spec_version', StringProperty(fixed='2.1')),
         ('id', IDProperty(_type, spec_version='2.1')),
         ('created_by_ref', ReferenceProperty(valid_types='identity', spec_version='2.1')),
@@ -76,7 +76,7 @@ class Sighting(_RelationshipObject):
 
     _type = 'sighting'
     _properties = OrderedDict([
-        ('type', TypeProperty(_type)),
+        ('type', TypeProperty(_type, spec_version='2.1')),
         ('spec_version', StringProperty(fixed='2.1')),
         ('id', IDProperty(_type, spec_version='2.1')),
         ('created_by_ref', ReferenceProperty(valid_types='identity', spec_version='2.1')),