diff --git a/rosidl_generator_py/resource/_action.py.em b/rosidl_generator_py/resource/_action.py.em
index 0a081993..923396fa 100644
--- a/rosidl_generator_py/resource/_action.py.em
+++ b/rosidl_generator_py/resource/_action.py.em
@@ -50,7 +50,7 @@ class Metaclass_@(action.namespaced_type.name)(rosidl_pycommon.interface_base_cl
     @@classmethod
     def __import_type_support__(cls) -> None:
         try:
-            from rosidl_generator_py import import_type_support
+            from rosidl_generator_py import import_type_support  # type: ignore[attr-defined]
             module = import_type_support('@(package_name)')
         except ImportError:
             import logging
diff --git a/rosidl_generator_py/resource/_idl.py.em b/rosidl_generator_py/resource/_idl.py.em
index 98fb0b13..e2e24720 100644
--- a/rosidl_generator_py/resource/_idl.py.em
+++ b/rosidl_generator_py/resource/_idl.py.em
@@ -5,15 +5,22 @@
 from __future__ import annotations
 
 import collections.abc
-from os import getenv
+import os
 import typing
 
 import rosidl_pycommon.interface_base_classes
 
+if typing.TYPE_CHECKING:
+    from ctypes import Structure
+
+    class PyCapsule(Structure):
+        pass  # don't need to define the full structure
+
+
 # This is being done at the module level and not on the instance level to avoid looking
 # for the same variable multiple times on each instance. This variable is not supposed to
 # change during runtime so it makes sense to only look for it once.
-ros_python_check_fields = getenv('ROS_PYTHON_CHECK_FIELDS', default='')
+ros_python_check_fields = os.getenv('ROS_PYTHON_CHECK_FIELDS', default='')
 @
 @#######################################################################
 @# EmPy template for generating _<idl>.py files
diff --git a/rosidl_generator_py/resource/_msg.py.em b/rosidl_generator_py/resource/_msg.py.em
index 98285ecb..902cace3 100644
--- a/rosidl_generator_py/resource/_msg.py.em
+++ b/rosidl_generator_py/resource/_msg.py.em
@@ -38,13 +38,6 @@ type_annotations_setter: dict[str, str] = {}
 type_annotations_getter: dict[str, str] = {}
 type_imports: set[str] = set()
 
-# Types which always exist
-# Done in one multi-line string to preserve order
-type_imports.add(
-    """from ctypes import Structure
-
-    class PyCapsule(Structure):
-        pass  # don't need to define the full structure""")
 for member in message.structure.members:
     setter_type, getter_type = get_setter_and_getter_type(member, type_imports)
     type_annotations_setter[member.name] = setter_type
@@ -63,21 +56,18 @@ for member in message.structure.members:
 }@
 @{
 suffix = '__'.join(message.structure.namespaced_type.namespaces[1:]) + '__' + convert_camel_case_to_lower_case_underscore(message.structure.namespaced_type.name)
-type_annotations_import_statements_copy = type_annotations_import_statements.copy()
+new_typing_imports = sorted(type_imports - type_annotations_import_statements)
 }@
+@[if new_typing_imports]@
 
 
 if typing.TYPE_CHECKING:
-@[for type_import in type_imports]@
-@[if type_import not in type_annotations_import_statements]@
-    @(type_import)
+@[  for type_import in new_typing_imports]@
+    @(type_import)  # noqa: E402, I300
 @{
 type_annotations_import_statements.add(type_import)
 }@
-@[end if]@
-@[end for]@
-@[if type_annotations_import_statements == type_annotations_import_statements_copy]@
-    pass
+@[  end for]@
 @[end if]@
 @#<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
 @# Collect necessary import statements for all members
diff --git a/rosidl_generator_py/resource/_srv.py.em b/rosidl_generator_py/resource/_srv.py.em
index 3320ff22..d20a467a 100644
--- a/rosidl_generator_py/resource/_srv.py.em
+++ b/rosidl_generator_py/resource/_srv.py.em
@@ -46,7 +46,7 @@ class Metaclass_@(service.namespaced_type.name)(rosidl_pycommon.interface_base_c
     @@classmethod
     def __import_type_support__(cls) -> None:
         try:
-            from rosidl_generator_py import import_type_support
+            from rosidl_generator_py import import_type_support  # type: ignore[attr-defined]
             module = import_type_support('@(package_name)')
         except ImportError:
             import logging