diff --git a/stix2/properties.py b/stix2/properties.py
index 9f8849b..4f1ebd2 100644
--- a/stix2/properties.py
+++ b/stix2/properties.py
@@ -9,7 +9,6 @@ import re
 import uuid
 
 from six import string_types, text_type
-from stix2patterns.validator import run_validator
 
 import stix2
 
@@ -558,16 +557,8 @@ class EnumProperty(StringProperty):
 
 class PatternProperty(StringProperty):
 
-    def __init__(self, spec_version=stix2.DEFAULT_VERSION, **kwargs):
-        self.spec_version = spec_version
-        super(PatternProperty, self).__init__(**kwargs)
-
     def clean(self, value):
         cleaned_value = super(PatternProperty, self).clean(value)
-        errors = run_validator(cleaned_value, self.spec_version)
-        if errors:
-            raise ValueError(str(errors[0]))
-
         return cleaned_value
 
 
diff --git a/stix2/v20/sdo.py b/stix2/v20/sdo.py
index c1f480d..430bfc0 100644
--- a/stix2/v20/sdo.py
+++ b/stix2/v20/sdo.py
@@ -3,8 +3,11 @@
 from collections import OrderedDict
 import itertools
 
+from stix2patterns.validator import run_validator
+
 from ..core import STIXDomainObject
 from ..custom import _custom_object_builder
+from ..exceptions import InvalidValueError
 from ..properties import (
     BooleanProperty, IDProperty, IntegerProperty, ListProperty,
     ObservableProperty, PatternProperty, ReferenceProperty, StringProperty,
@@ -124,7 +127,7 @@ class Indicator(STIXDomainObject):
         ('modified', TimestampProperty(default=lambda: NOW, precision='millisecond')),
         ('name', StringProperty()),
         ('description', StringProperty()),
-        ('pattern', PatternProperty(required=True, spec_version='2.0')),
+        ('pattern', PatternProperty(required=True)),
         ('valid_from', TimestampProperty(default=lambda: NOW)),
         ('valid_until', TimestampProperty()),
         ('kill_chain_phases', ListProperty(KillChainPhase)),
@@ -135,6 +138,11 @@ class Indicator(STIXDomainObject):
         ('granular_markings', ListProperty(GranularMarking)),
     ])
 
+    def _check_object_constraints(self):
+        errors = run_validator(self.get('pattern'), '2.0')
+        if errors:
+            raise InvalidValueError(self.__class__, 'pattern', str(errors[0]))
+
 
 class IntrusionSet(STIXDomainObject):
     """For more detailed information on this object's properties, see
diff --git a/stix2/v21/sdo.py b/stix2/v21/sdo.py
index 250d4a1..1d97261 100644
--- a/stix2/v21/sdo.py
+++ b/stix2/v21/sdo.py
@@ -5,10 +5,13 @@ import itertools
 import warnings
 
 from six.moves.urllib.parse import quote_plus
+from stix2patterns.validator import run_validator
 
 from ..core import STIXDomainObject
 from ..custom import _custom_object_builder
-from ..exceptions import PropertyPresenceError, STIXDeprecationWarning
+from ..exceptions import (
+    InvalidValueError, PropertyPresenceError, STIXDeprecationWarning,
+)
 from ..properties import (
     BinaryProperty, BooleanProperty, EmbeddedObjectProperty, EnumProperty,
     FloatProperty, IDProperty, IntegerProperty, ListProperty,
@@ -200,7 +203,7 @@ class Indicator(STIXDomainObject):
         ('name', StringProperty()),
         ('description', StringProperty()),
         ('indicator_types', ListProperty(StringProperty, required=True)),
-        ('pattern', PatternProperty(required=True, spec_version='2.1')),
+        ('pattern', PatternProperty(required=True)),
         ('pattern_type', StringProperty(required=True)),
         ('pattern_version', StringProperty()),
         ('valid_from', TimestampProperty(default=lambda: NOW, required=True)),
@@ -232,6 +235,16 @@ class Indicator(STIXDomainObject):
             msg = "{0.id} 'valid_until' must be greater than 'valid_from'"
             raise ValueError(msg.format(self))
 
+        if self.get('pattern_type') == "stix":
+            try:
+                pat_ver = self.get('pattern_version')
+            except AttributeError:
+                pat_ver = '2.1'
+
+            errors = run_validator(self.get('pattern'), pat_ver)
+            if errors:
+                raise InvalidValueError(self.__class__, 'pattern', str(errors[0]))
+
 
 class Infrastructure(STIXDomainObject):
     # TODO: Add link