diff --git a/changelogs/fragments/1163-map_complex_type.yml b/changelogs/fragments/1163-map_complex_type.yml
new file mode 100644
index 00000000000..6315b24128f
--- /dev/null
+++ b/changelogs/fragments/1163-map_complex_type.yml
@@ -0,0 +1,2 @@
+bugfixes:
+- module_utils.transformations - ensure that ``map_complex_type`` still returns transformed items if items exists that are not in the type_map (https://github.com/ansible-collections/amazon.aws/pull/1163).
diff --git a/plugins/module_utils/transformation.py b/plugins/module_utils/transformation.py
index e768844fa6f..70d38cd8abb 100644
--- a/plugins/module_utils/transformation.py
+++ b/plugins/module_utils/transformation.py
@@ -104,7 +104,7 @@ def map_complex_type(complex_type, type_map):
                         complex_type[key],
                         type_map[key])
             else:
-                return complex_type
+                new_type[key] = complex_type[key]
     elif isinstance(complex_type, list):
         for i in range(len(complex_type)):
             new_type.append(map_complex_type(
diff --git a/tests/unit/module_utils/cloud/test_cloud_retry.py b/tests/unit/module_utils/cloud/test_cloud_retry.py
index 71b4e655ce3..ce5f03f1196 100644
--- a/tests/unit/module_utils/cloud/test_cloud_retry.py
+++ b/tests/unit/module_utils/cloud/test_cloud_retry.py
@@ -18,7 +18,7 @@ class TestCloudRetry():
     error_codes = [400, 500, 600]
     custom_error_codes = [100, 200, 300]
 
-    class TestException(Exception):
+    class OurTestException(Exception):
         """
         custom exception class for testing
         """
@@ -81,7 +81,7 @@ def test_retry_backoff(self):
         def test_retry_func():
             if test_retry_func.counter < 2:
                 test_retry_func.counter += 1
-                raise self.TestException(status=random.choice(TestCloudRetry.error_codes))
+                raise self.OurTestException(status=random.choice(TestCloudRetry.error_codes))
             else:
                 return True
 
@@ -99,7 +99,7 @@ def test_retry_exponential_backoff(self):
         def test_retry_func():
             if test_retry_func.counter < 2:
                 test_retry_func.counter += 1
-                raise self.TestException(status=random.choice(TestCloudRetry.error_codes))
+                raise self.OurTestException(status=random.choice(TestCloudRetry.error_codes))
             else:
                 return True
 
@@ -108,19 +108,19 @@ def test_retry_func():
         assert ret is True
 
     def test_retry_exponential_backoff_with_unexpected_exception(self):
-        unexpected_except = self.TestException(status=100)
+        unexpected_except = self.OurTestException(status=100)
 
         @TestCloudRetry.UnitTestsRetry.exponential_backoff(retries=3, delay=1, backoff=1.1, max_delay=3,
                                                            catch_extra_error_codes=TestCloudRetry.error_codes)
         def test_retry_func():
             if test_retry_func.counter == 0:
                 test_retry_func.counter += 1
-                raise self.TestException(status=random.choice(TestCloudRetry.error_codes))
+                raise self.OurTestException(status=random.choice(TestCloudRetry.error_codes))
             else:
                 raise unexpected_except
 
         test_retry_func.counter = 0
-        with pytest.raises(self.TestException) as context:
+        with pytest.raises(self.OurTestException) as context:
             test_retry_func()
 
         assert context.value.status == unexpected_except.status
@@ -134,7 +134,7 @@ def test_retry_jitter_backoff(self):
         def test_retry_func():
             if test_retry_func.counter < 2:
                 test_retry_func.counter += 1
-                raise self.TestException(status=random.choice(TestCloudRetry.error_codes))
+                raise self.OurTestException(status=random.choice(TestCloudRetry.error_codes))
             else:
                 return True
 
@@ -143,19 +143,19 @@ def test_retry_func():
         assert ret is True
 
     def test_retry_jittered_backoff_with_unexpected_exception(self):
-        unexpected_except = self.TestException(status=100)
+        unexpected_except = self.OurTestException(status=100)
 
         @TestCloudRetry.UnitTestsRetry.jittered_backoff(retries=3, delay=1, max_delay=3,
                                                         catch_extra_error_codes=TestCloudRetry.error_codes)
         def test_retry_func():
             if test_retry_func.counter == 0:
                 test_retry_func.counter += 1
-                raise self.TestException(status=random.choice(TestCloudRetry.error_codes))
+                raise self.OurTestException(status=random.choice(TestCloudRetry.error_codes))
             else:
                 raise unexpected_except
 
         test_retry_func.counter = 0
-        with pytest.raises(self.TestException) as context:
+        with pytest.raises(self.OurTestException) as context:
             test_retry_func()
 
         assert context.value.status == unexpected_except.status
@@ -172,7 +172,7 @@ def build_response():
         def test_retry_func():
             if test_retry_func.counter < 2:
                 test_retry_func.counter += 1
-                raise self.TestException(build_response())
+                raise self.OurTestException(build_response())
             else:
                 return True
 
@@ -188,13 +188,13 @@ def test_wrapped_function_called_several_times(self):
         @TestCloudRetry.UnitTestsRetry.exponential_backoff(retries=2, delay=2, backoff=4, max_delay=100,
                                                            catch_extra_error_codes=TestCloudRetry.error_codes)
         def _fail():
-            raise self.TestException(status=random.choice(TestCloudRetry.error_codes))
+            raise self.OurTestException(status=random.choice(TestCloudRetry.error_codes))
 
         # run the method 3 times and assert that each it is retrying after 2secs
         # the elapsed execution time should be closed to 2sec
         for _i in range(3):
             start = datetime.now()
-            with pytest.raises(self.TestException):
+            with pytest.raises(self.OurTestException):
                 _fail()
             duration = (datetime.now() - start).seconds
             assert duration == 2
diff --git a/tests/unit/module_utils/transformation/test_ansible_dict_to_boto3_filter_list.py b/tests/unit/module_utils/transformation/test_ansible_dict_to_boto3_filter_list.py
index 3c19089231f..23c82b173b2 100644
--- a/tests/unit/module_utils/transformation/test_ansible_dict_to_boto3_filter_list.py
+++ b/tests/unit/module_utils/transformation/test_ansible_dict_to_boto3_filter_list.py
@@ -10,7 +10,7 @@
 from ansible_collections.amazon.aws.plugins.module_utils.transformation import ansible_dict_to_boto3_filter_list
 
 
-class AnsibleDictToBoto3FilterListTestSuite():
+class TestAnsibleDictToBoto3FilterList():
 
     # ========================================================
     #   ec2.ansible_dict_to_boto3_filter_list
@@ -28,7 +28,7 @@ def test_ansible_dict_with_string_to_boto3_filter_list(self):
         ]
 
         converted_filters_list = ansible_dict_to_boto3_filter_list(filters)
-        self.assertEqual(converted_filters_list, filter_list_string)
+        assert converted_filters_list == filter_list_string
 
     def test_ansible_dict_with_boolean_to_boto3_filter_list(self):
         filters = {'enabled': True}
@@ -42,7 +42,7 @@ def test_ansible_dict_with_boolean_to_boto3_filter_list(self):
         ]
 
         converted_filters_bool = ansible_dict_to_boto3_filter_list(filters)
-        self.assertEqual(converted_filters_bool, filter_list_boolean)
+        assert converted_filters_bool == filter_list_boolean
 
     def test_ansible_dict_with_integer_to_boto3_filter_list(self):
         filters = {'version': 1}
@@ -56,4 +56,18 @@ def test_ansible_dict_with_integer_to_boto3_filter_list(self):
         ]
 
         converted_filters_int = ansible_dict_to_boto3_filter_list(filters)
-        self.assertEqual(converted_filters_int, filter_list_integer)
+        assert converted_filters_int == filter_list_integer
+
+    def test_ansible_dict_with_list_to_boto3_filter_list(self):
+        filters = {'version': ['1', '2', '3']}
+        filter_list_integer = [
+            {
+                'Name': 'version',
+                'Values': [
+                    '1', '2', '3'
+                ]
+            }
+        ]
+
+        converted_filters_int = ansible_dict_to_boto3_filter_list(filters)
+        assert converted_filters_int == filter_list_integer
diff --git a/tests/unit/module_utils/transformation/test_map_complex_type.py b/tests/unit/module_utils/transformation/test_map_complex_type.py
index 32635d47acd..2300e2351dd 100644
--- a/tests/unit/module_utils/transformation/test_map_complex_type.py
+++ b/tests/unit/module_utils/transformation/test_map_complex_type.py
@@ -8,14 +8,93 @@
 
 from ansible_collections.amazon.aws.plugins.module_utils.transformation import map_complex_type
 
+from ansible_collections.amazon.aws.tests.unit.compat.mock import sentinel
 
-class TestMapComplexTypeTestSuite():
 
-    def test_map_complex_type_over_dict(self):
-        type_map = {'minimum_healthy_percent': 'int', 'maximum_percent': 'int'}
-        complex_type_dict = {'minimum_healthy_percent': "75", 'maximum_percent': "150"}
-        complex_type_expected = {'minimum_healthy_percent': 75, 'maximum_percent': 150}
+def test_map_complex_type_over_dict():
+    type_map = {'minimum_healthy_percent': 'int', 'maximum_percent': 'int'}
+    complex_type_dict = {'minimum_healthy_percent': "75", 'maximum_percent': "150"}
+    complex_type_expected = {'minimum_healthy_percent': 75, 'maximum_percent': 150}
 
-        complex_type_mapped = map_complex_type(complex_type_dict, type_map)
+    complex_type_mapped = map_complex_type(complex_type_dict, type_map)
 
-        assert complex_type_mapped == complex_type_expected
+    assert complex_type_mapped == complex_type_expected
+
+
+def test_map_complex_type_empty():
+    type_map = {'minimum_healthy_percent': 'int', 'maximum_percent': 'int'}
+    assert map_complex_type({}, type_map) == {}
+    assert map_complex_type([], type_map) == []
+    assert map_complex_type(None, type_map) is None
+
+
+def test_map_complex_type_no_type():
+    type_map = {'some_entry': 'int'}
+    complex_dict = {'another_entry': sentinel.UNSPECIFIED_MAPPING}
+    mapped_dict = map_complex_type(complex_dict, type_map)
+    assert mapped_dict == complex_dict
+    # we should have the original sentinel object, even if it's a new dictionary
+    assert mapped_dict['another_entry'] is sentinel.UNSPECIFIED_MAPPING
+
+
+def test_map_complex_type_list():
+    type_map = {'some_entry': 'int'}
+    complex_dict = {'some_entry': ["1", "2", "3"]}
+    expected_dict = {'some_entry': [1, 2, 3]}
+    mapped_dict = map_complex_type(complex_dict, type_map)
+    assert mapped_dict == expected_dict
+
+
+def test_map_complex_type_list_type():
+    type_map = {'some_entry': ['int']}
+    complex_dict = {'some_entry': ["1", "2", "3"]}
+    expected_dict = {'some_entry': [1, 2, 3]}
+    mapped_dict = map_complex_type(complex_dict, type_map)
+    assert mapped_dict == expected_dict
+
+    type_map = {'some_entry': ['int']}
+    complex_dict = {'some_entry': "1"}
+    expected_dict = {'some_entry': 1}
+    mapped_dict = map_complex_type(complex_dict, type_map)
+    assert mapped_dict == expected_dict
+
+
+def test_map_complex_type_complex():
+    type_map = {
+        'my_integer': 'int',
+        'my_bool': 'bool',
+        'my_string': 'str',
+        'my_typelist_of_int': ['int'],
+        'my_maplist_of_int': 'int',
+        'my_unused': 'bool',
+    }
+    complex_dict = {
+        'my_integer': '-24',
+        'my_bool': 'true',
+        'my_string': 43,
+        'my_typelist_of_int': '5',
+        'my_maplist_of_int': ['-26', '47'],
+        'my_unconverted': sentinel.UNSPECIFIED_MAPPING,
+    }
+    expected_dict = {
+        'my_integer': -24,
+        'my_bool': True,
+        'my_string': '43',
+        'my_typelist_of_int': 5,
+        'my_maplist_of_int': [-26, 47],
+        'my_unconverted': sentinel.UNSPECIFIED_MAPPING,
+    }
+
+    mapped_dict = map_complex_type(complex_dict, type_map)
+
+    assert mapped_dict == expected_dict
+    assert mapped_dict['my_unconverted'] is sentinel.UNSPECIFIED_MAPPING
+    assert mapped_dict['my_bool'] is True
+
+
+def test_map_complex_type_nested_list():
+    type_map = {'my_integer': 'int'}
+    complex_dict = [{'my_integer': '5'}, {'my_integer': '-24'}]
+    expected_dict = [{'my_integer': 5}, {'my_integer': -24}]
+    mapped_dict = map_complex_type(complex_dict, type_map)
+    assert mapped_dict == expected_dict