diff --git a/rosidl_generator_py/CMakeLists.txt b/rosidl_generator_py/CMakeLists.txt
index e5ff834f..e0d0f723 100644
--- a/rosidl_generator_py/CMakeLists.txt
+++ b/rosidl_generator_py/CMakeLists.txt
@@ -14,6 +14,7 @@ ament_python_install_package(${PROJECT_NAME})
 if(BUILD_TESTING)
   find_package(ament_cmake_pytest REQUIRED)
 
+  find_package(builtin_interfaces REQUIRED)
   find_package(rmw REQUIRED)
   find_package(rosidl_cmake REQUIRED)
 
@@ -47,8 +48,11 @@ if(BUILD_TESTING)
       ${test_interface_files_MSG_FILES}
       # Cases not covered by test_interface_files
       msg/BuiltinTypeSequencesIdl.idl
+      msg/Duration.msg
+      msg/DurationArraySequence.msg
       msg/StringArrays.msg
       msg/Property.msg
+      DEPENDENCIES builtin_interfaces
       ADD_LINTER_TESTS
       SKIP_INSTALL
     )
diff --git a/rosidl_generator_py/msg/Duration.msg b/rosidl_generator_py/msg/Duration.msg
new file mode 100644
index 00000000..cbe51b2c
--- /dev/null
+++ b/rosidl_generator_py/msg/Duration.msg
@@ -0,0 +1 @@
+builtin_interfaces/Duration data
diff --git a/rosidl_generator_py/msg/DurationArraySequence.msg b/rosidl_generator_py/msg/DurationArraySequence.msg
new file mode 100644
index 00000000..e49baa20
--- /dev/null
+++ b/rosidl_generator_py/msg/DurationArraySequence.msg
@@ -0,0 +1,2 @@
+builtin_interfaces/Duration[2] array_data
+builtin_interfaces/Duration[] sequence_data
diff --git a/rosidl_generator_py/package.xml b/rosidl_generator_py/package.xml
index 2f46115d..a1d8cee4 100644
--- a/rosidl_generator_py/package.xml
+++ b/rosidl_generator_py/package.xml
@@ -53,6 +53,7 @@
   <test_depend>ament_index_python</test_depend>
   <test_depend>ament_lint_auto</test_depend>
   <test_depend>ament_lint_common</test_depend>
+  <test_depend>builtin_interfaces</test_depend>
   <test_depend>python3-numpy</test_depend>
   <test_depend>python3-pytest</test_depend>
   <test_depend>rmw</test_depend>
diff --git a/rosidl_generator_py/resource/_msg.py.em b/rosidl_generator_py/resource/_msg.py.em
index a8682df0..e093a3e6 100644
--- a/rosidl_generator_py/resource/_msg.py.em
+++ b/rosidl_generator_py/resource/_msg.py.em
@@ -30,6 +30,27 @@ from rosidl_parser.definition import NamespacedType
 from rosidl_parser.definition import SIGNED_INTEGER_TYPES
 from rosidl_parser.definition import UnboundedSequence
 from rosidl_parser.definition import UNSIGNED_INTEGER_TYPES
+
+
+def get_importable_namespaced_type(
+    type_: NamespacedType,
+    action_goal_suffix: str = ACTION_GOAL_SUFFIX,
+    action_result_suffix: str = ACTION_RESULT_SUFFIX,
+    action_feedback_suffix: str = ACTION_FEEDBACK_SUFFIX,
+    camel_to_snake=convert_camel_case_to_lower_case_underscore,
+) -> tuple[str, str]:
+    joined_type_namespaces = '.'.join(type_.namespaces)
+    if (
+        type_.name.endswith(action_goal_suffix) or
+        type_.name.endswith(action_result_suffix) or
+        type_.name.endswith(action_feedback_suffix)
+    ):
+        action_name, _ = type_.name.rsplit('_', 1)
+        lower_case_name = camel_to_snake(action_name)
+        module_name = f'{joined_type_namespaces}._{lower_case_name}'
+    else:
+        module_name = joined_type_namespaces
+    return module_name, f'{module_name}.{type_.name}'
 }@
 @{
 import_type_checking = False
@@ -182,22 +203,13 @@ for member in message.structure.members:
             type_.name.endswith(SERVICE_REQUEST_MESSAGE_SUFFIX)
         ):
             continue
-        if (
-            type_.name.endswith(ACTION_GOAL_SUFFIX) or
-            type_.name.endswith(ACTION_RESULT_SUFFIX) or
-            type_.name.endswith(ACTION_FEEDBACK_SUFFIX)
-        ):
-            action_name, suffix = type_.name.rsplit('_', 1)
-            typename = (*type_.namespaces, action_name, action_name + '.' + suffix)
-        else:
-            typename = (*type_.namespaces, type_.name, type_.name)
-        importable_typesupports.add(typename)
+        importable_typesupports.add(get_importable_namespaced_type(type_))
 }@
-@[for typename in sorted(importable_typesupports)]@
+@[for module_name, type_name in sorted(importable_typesupports)]@
 
-            from @('.'.join(typename[:-2])) import @(typename[-2])
-            if @(typename[-1])._TYPE_SUPPORT is None:
-                @(typename[-1]).__import_type_support__()
+            import @(module_name)
+            if @(type_name)._TYPE_SUPPORT is None:
+                @(type_name).__import_type_support__()
 @[end for]@
 
     @@classmethod
@@ -370,15 +382,10 @@ if isinstance(type_, AbstractNestedType):
         self.@(member.name) = @(member.name) if @(member.name) is not None else @(message.structure.namespaced_type.name).@(member.name.upper())__DEFAULT
 @[  else]@
 @[    if isinstance(type_, NamespacedType) and not isinstance(member.type, AbstractSequence)]@
-@[      if (
-            type_.name.endswith(ACTION_GOAL_SUFFIX) or
-            type_.name.endswith(ACTION_RESULT_SUFFIX) or
-            type_.name.endswith(ACTION_FEEDBACK_SUFFIX)
-        )]@
-        from @('.'.join(type_.namespaces))._@(convert_camel_case_to_lower_case_underscore(type_.name.rsplit('_', 1)[0])) import @(type_.name)
-@[      else]@
-        from @('.'.join(type_.namespaces)) import @(type_.name)
-@[      end if]@
+@{
+module_name, type_name = get_importable_namespaced_type(type_)
+}@
+        import @(module_name)
 @[    end if]@
 @[    if isinstance(member.type, Array)]@
 @[      if isinstance(type_, BasicType) and type_.typename == 'octet']@
@@ -392,7 +399,8 @@ if isinstance(type_, AbstractNestedType):
         else:
             self.@(member.name) = @(member.name)
 @[        else]@
-        self.@(member.name) = @(member.name) if @(member.name) is not None else [@(get_python_type(type_))() for x in range(@(member.type.size))]
+@{default_type = type_name if isinstance(type_, NamespacedType) else get_python_type(type_)}@
+        self.@(member.name) = @(member.name) if @(member.name) is not None else [@(default_type)() for x in range(@(member.type.size))]
 @[        end if]@
 @[      end if]@
 @[    elif isinstance(member.type, AbstractSequence)]@
@@ -405,6 +413,8 @@ if isinstance(type_, AbstractNestedType):
         self.@(member.name) = @(member.name) if @(member.name) is not None else bytes([0])
 @[    elif isinstance(type_, BasicType) and type_.typename in CHARACTER_TYPES]@
         self.@(member.name) = @(member.name) if @(member.name) is not None else chr(0)
+@[    elif isinstance(type_, NamespacedType)]@
+        self.@(member.name) = @(member.name) if @(member.name) is not None else @(type_name)()
 @[    else]@
         self.@(member.name) = @(member.name) if @(member.name) is not None else @(get_python_type(type_))()
 @[    end if]@
@@ -504,15 +514,10 @@ if isinstance(member.type, (Array, AbstractSequence)):
 @[    end if]@
 @[  end if]@
 @[  if isinstance(type_, NamespacedType)]@
-@[      if (
-            type_.name.endswith(ACTION_GOAL_SUFFIX) or
-            type_.name.endswith(ACTION_RESULT_SUFFIX) or
-            type_.name.endswith(ACTION_FEEDBACK_SUFFIX)
-        )]@
-        from @('.'.join(type_.namespaces))._@(convert_camel_case_to_lower_case_underscore(type_.name.rsplit('_', 1)[0])) import @(type_.name)
-@[      else]@
-        from @('.'.join(type_.namespaces)) import @(type_.name)
-@[      end if]@
+@{
+module_name, type_name = get_importable_namespaced_type(type_)
+}@
+        import @(module_name)
 @[  end if]@
 
 @{
diff --git a/rosidl_generator_py/resource/_msg_check_fields.py.em b/rosidl_generator_py/resource/_msg_check_fields.py.em
index 50ad4128..ece3b37f 100644
--- a/rosidl_generator_py/resource/_msg_check_fields.py.em
+++ b/rosidl_generator_py/resource/_msg_check_fields.py.em
@@ -3,6 +3,9 @@ from rosidl_parser.definition import AbstractGenericString
 from rosidl_parser.definition import AbstractNestedType
 from rosidl_parser.definition import AbstractSequence
 from rosidl_parser.definition import Array
+from rosidl_parser.definition import ACTION_FEEDBACK_SUFFIX
+from rosidl_parser.definition import ACTION_GOAL_SUFFIX
+from rosidl_parser.definition import ACTION_RESULT_SUFFIX
 from rosidl_parser.definition import BasicType
 from rosidl_parser.definition import BOOLEAN_TYPE
 from rosidl_parser.definition import INTEGER_TYPES
@@ -11,8 +14,35 @@ from rosidl_parser.definition import FLOATING_POINT_TYPES
 from rosidl_parser.definition import SIGNED_INTEGER_TYPES
 from rosidl_parser.definition import UNSIGNED_INTEGER_TYPES
 from rosidl_parser.definition import NamespacedType
+from rosidl_pycommon import convert_camel_case_to_lower_case_underscore
 from rosidl_generator_py.generate_py_impl import get_python_type
 from rosidl_generator_py.generate_py_impl import SPECIAL_NESTED_BASIC_TYPES
+
+
+def get_importable_namespaced_type(
+    type_: NamespacedType,
+    action_goal_suffix: str = ACTION_GOAL_SUFFIX,
+    action_result_suffix: str = ACTION_RESULT_SUFFIX,
+    action_feedback_suffix: str = ACTION_FEEDBACK_SUFFIX,
+    camel_to_snake=convert_camel_case_to_lower_case_underscore,
+) -> tuple[str, str]:
+    joined_type_namespaces = '.'.join(type_.namespaces)
+    if (
+        type_.name.endswith(action_goal_suffix) or
+        type_.name.endswith(action_result_suffix) or
+        type_.name.endswith(action_feedback_suffix)
+    ):
+        action_name, _ = type_.name.rsplit('_', 1)
+        lower_case_name = camel_to_snake(action_name)
+        module_name = f'{joined_type_namespaces}._{lower_case_name}'
+    else:
+        module_name = joined_type_namespaces
+    return module_name, f'{module_name}.{type_.name}'
+}@
+@{
+python_type = get_python_type(type_)
+if isinstance(type_, NamespacedType):
+    _, python_type = get_importable_namespaced_type(type_)
 }@
         if self._check_fields:
 @[  if isinstance(member.type, AbstractNestedType)]@
@@ -61,8 +91,8 @@ from rosidl_generator_py.generate_py_impl import SPECIAL_NESTED_BASIC_TYPES
 @{assert_msg_suffixes.insert(1, 'with length %d' % member.type.size)}@
 @[        end if]@
 @[      end if]@
-                     all(isinstance(v, @(get_python_type(type_))) for v in value) and
-@{assert_msg_suffixes.append("and each value of type '%s'" % get_python_type(type_))}@
+                     all(isinstance(v, @(python_type)) for v in value) and
+@{assert_msg_suffixes.append("and each value of type '%s'" % python_type)}@
 @[      if isinstance(type_, BasicType) and type_.typename in SIGNED_INTEGER_TYPES]@
 @{
 nbits = int(type_.typename[3:])
@@ -106,7 +136,7 @@ bound = 1.7976931348623157e+308
                     "The '@(member.name)' field must be string value " \
                     'not longer than @(type_.maximum_size)'
 @[  elif isinstance(type_, NamespacedType)]@
-                    isinstance(value, @(type_.name)), \
+                    isinstance(value, @(python_type)), \
                     "The '@(member.name)' field must be a sub message of type '@(type_.name)'"
 @[  elif isinstance(type_, BasicType) and type_.typename == 'octet']@
                     (isinstance(value, (bytes, bytearray, memoryview)) and
diff --git a/rosidl_generator_py/test/test_interfaces.py b/rosidl_generator_py/test/test_interfaces.py
index 64225d9c..d3ae7083 100644
--- a/rosidl_generator_py/test/test_interfaces.py
+++ b/rosidl_generator_py/test/test_interfaces.py
@@ -14,6 +14,7 @@
 
 import array
 import math
+import pathlib
 import sys
 
 import numpy
@@ -25,6 +26,8 @@
 from rosidl_generator_py.msg import BuiltinTypeSequencesIdl
 from rosidl_generator_py.msg import Constants
 from rosidl_generator_py.msg import Defaults
+from rosidl_generator_py.msg import Duration
+from rosidl_generator_py.msg import DurationArraySequence
 from rosidl_generator_py.msg import Nested
 from rosidl_generator_py.msg import StringArrays
 from rosidl_generator_py.msg import Strings
@@ -269,6 +272,48 @@ def test_constructor() -> None:
         Strings(unknown_field='test', check_fields=True)
 
 
+def test_namespaced_field_imports_are_absolute() -> None:
+    duration_module = sys.modules[Duration.__module__]
+    duration_file = duration_module.__file__
+    assert duration_file is not None
+    duration_source = pathlib.Path(duration_file).read_text(encoding='utf-8')
+
+    assert 'from builtin_interfaces.msg import Duration' not in duration_source
+    assert 'import builtin_interfaces.msg' in duration_source
+    assert 'builtin_interfaces.msg.Duration._TYPE_SUPPORT' in duration_source
+
+    from builtin_interfaces.msg import Duration as BuiltinDuration
+
+    Duration.__import_type_support__()
+
+    msg = Duration(check_fields=True)
+    assert isinstance(msg.data, BuiltinDuration)
+
+
+def test_namespaced_array_sequence_fields_are_absolute() -> None:
+    duration_module = sys.modules[DurationArraySequence.__module__]
+    duration_file = duration_module.__file__
+    assert duration_file is not None
+    duration_source = pathlib.Path(duration_file).read_text(encoding='utf-8')
+
+    assert 'from builtin_interfaces.msg import Duration' not in duration_source
+    assert 'import builtin_interfaces.msg' in duration_source
+
+    from builtin_interfaces.msg import Duration as BuiltinDuration
+
+    msg = DurationArraySequence(check_fields=True)
+    assert all(isinstance(value, BuiltinDuration) for value in msg.array_data)
+    assert [] == msg.sequence_data
+
+    msg.array_data = [BuiltinDuration(sec=1), BuiltinDuration(sec=2)]
+    msg.sequence_data = [BuiltinDuration(sec=3)]
+
+    with pytest.raises(AssertionError):
+        msg.array_data = [BuiltinDuration(), object()]
+    with pytest.raises(AssertionError):
+        msg.sequence_data = [object()]
+
+
 def test_constants() -> None:
     assert Constants.BOOL_CONST is True
     assert bytes([50]) == Constants.BYTE_CONST