diff --git a/apimatic_core/utilities/api_helper.py b/apimatic_core/utilities/api_helper.py
index 9b0609d..dde1d0d 100644
--- a/apimatic_core/utilities/api_helper.py
+++ b/apimatic_core/utilities/api_helper.py
@@ -556,7 +556,10 @@ def is_file_wrapper_instance(param):
         return isinstance(param, FileWrapper)
 
     @staticmethod
-    def is_valid_type(value, type_callable):
+    def is_valid_type(value, type_callable, is_value_nullable=False):
+        if value is None and is_value_nullable:
+            return True
+
         if isinstance(value, list):
             return all(ApiHelper.is_valid_type(item, type_callable) for item in value)
         elif isinstance(value, dict):
diff --git a/setup.py b/setup.py
index b9213eb..b637602 100644
--- a/setup.py
+++ b/setup.py
@@ -12,7 +12,7 @@
 
 setup(
     name='apimatic-core',
-    version='0.2.7',
+    version='0.2.8',
     description='A library that contains core logic and utilities for '
                 'consuming REST APIs using Python SDKs generated by APIMatic.',
     long_description=long_description,
diff --git a/tests/apimatic_core/utility_tests/test_api_helper.py b/tests/apimatic_core/utility_tests/test_api_helper.py
index 7b44126..3c86a8e 100644
--- a/tests/apimatic_core/utility_tests/test_api_helper.py
+++ b/tests/apimatic_core/utility_tests/test_api_helper.py
@@ -849,38 +849,40 @@ def test_resolve_template_placeholders_using_json_pointer(self, input_placeholde
                                                                                     input_template)
         assert actual_message == expected_message
 
-    @pytest.mark.parametrize('input_value, input_callable, expected_value', [
-        (100, lambda value: isinstance(value, int), True),
-        ('100', lambda value: isinstance(value, str), True),
-        ("Sunday", lambda value: Days.validate(value), True),
-        (100.5, lambda value: isinstance(value, str), False),
-        ("Invalid", lambda value: Days.validate(value), False),
-        (None, lambda value: isinstance(value, str), False),
-        (None, None, False),
-
-        ([100, 200], lambda value: isinstance(value, int), True),
-        (['100', '200'], lambda value: isinstance(value, str), True),
-        (["Sunday", "Monday"], lambda value: Days.validate(value), True),
-        ([100.5, 200], lambda value: isinstance(value, str), False),
-        (["Invalid1", "Invalid2"], lambda value: Days.validate(value), False),
-        ([None, None], lambda value: isinstance(value, str), False),
-
-        ([[100, 200], [300, 400]], lambda value: isinstance(value, int), True),
-        ([['100', '200'], ['abc', 'def']], lambda value: isinstance(value, str), True),
-        ([["Sunday", "Monday"], ["Tuesday", "Friday"]], lambda value: Days.validate(value), True),
-        ([[100.5, 200], [400, 500]], lambda value: isinstance(value, str), False),
-        ([["Invalid1", "Invalid2"], ["Sunday", "Invalid4"]], lambda value: Days.validate(value), False),
-        ([[None, None], [None, None]], lambda value: isinstance(value, str), False),
-
-        ({'key0': 100, 'key2': 200}, lambda value: isinstance(value, int), True),
-        ({'key0': 'abc', 'key2': 'def'}, lambda value: isinstance(value, str), True),
-        ({'key0': 'Sunday', 'key2': 'Tuesday'}, lambda value: Days.validate(value), True),
-        ({'key0': 100.5, 'key2': 200}, lambda value: isinstance(value, str), False),
-        ({'key0': "Invalid1", 'key2': "Invalid2"}, lambda value: Days.validate(value), False),
-        ({'key0': None, 'key2': None}, lambda value: isinstance(value, str), False),
-    ])
-    def test_is_valid_type(self, input_value, input_callable, expected_value):
-        actual_value = ApiHelper.is_valid_type(input_value, input_callable)
+    @pytest.mark.parametrize('input_value, input_callable, is_value_nullable, expected_value', [
+        (100, lambda value: isinstance(value, int), False, True),
+        ('100', lambda value: isinstance(value, str), False, True),
+        ("Sunday", lambda value: Days.validate(value), False, True),
+        (100.5, lambda value: isinstance(value, str), False, False),
+        ("Invalid", lambda value: Days.validate(value), False, False),
+        (None, lambda value: isinstance(value, str), False, False),
+        (None, lambda value: isinstance(value, str), True, True),
+        (None, None, False, False),
+        (None, None, True, True),
+
+        ([100, 200], lambda value: isinstance(value, int), False, True),
+        (['100', '200'], lambda value: isinstance(value, str), False, True),
+        (["Sunday", "Monday"], lambda value: Days.validate(value), False, True),
+        ([100.5, 200], lambda value: isinstance(value, str), False, False),
+        (["Invalid1", "Invalid2"], lambda value: Days.validate(value), False, False),
+        ([None, None], lambda value: isinstance(value, str), False, False),
+
+        ([[100, 200], [300, 400]], lambda value: isinstance(value, int), False, True),
+        ([['100', '200'], ['abc', 'def']], lambda value: isinstance(value, str), False, True),
+        ([["Sunday", "Monday"], ["Tuesday", "Friday"]], lambda value: Days.validate(value), False, True),
+        ([[100.5, 200], [400, 500]], lambda value: isinstance(value, str), False, False),
+        ([["Invalid1", "Invalid2"], ["Sunday", "Invalid4"]], lambda value: Days.validate(value), False, False),
+        ([[None, None], [None, None]], lambda value: isinstance(value, str), False, False),
+
+        ({'key0': 100, 'key2': 200}, lambda value: isinstance(value, int), False, True),
+        ({'key0': 'abc', 'key2': 'def'}, lambda value: isinstance(value, str), False, True),
+        ({'key0': 'Sunday', 'key2': 'Tuesday'}, lambda value: Days.validate(value), False, True),
+        ({'key0': 100.5, 'key2': 200}, lambda value: isinstance(value, str), False, False),
+        ({'key0': "Invalid1", 'key2': "Invalid2"}, lambda value: Days.validate(value), False, False),
+        ({'key0': None, 'key2': None}, lambda value: isinstance(value, str), False, False),
+    ])
+    def test_is_valid_type(self, input_value, input_callable, is_value_nullable, expected_value):
+        actual_value = ApiHelper.is_valid_type(input_value, input_callable, is_value_nullable)
         assert actual_value == expected_value
 
     @pytest.mark.parametrize('input_value, input_union_type, input_should_deserialize, expected_value', [