diff --git a/rosidl_generator_py/resource/_msg.py.em b/rosidl_generator_py/resource/_msg.py.em
index a8682df0..2bf2a439 100644
--- a/rosidl_generator_py/resource/_msg.py.em
+++ b/rosidl_generator_py/resource/_msg.py.em
@@ -268,11 +268,7 @@ if isinstance(type_, AbstractNestedType):
     type_ = type_.value_type
 }@
         '@(member.name)': '@
-@# the prefix for nested types
-@[  if isinstance(member.type, AbstractSequence)]@
-sequence<@
-@[  end if]@
-@# the typename of the non-nested type or the nested basetype
+@# the typename of the non-nested type or the nested basetype (.msg syntax)
 @[  if isinstance(type_, BasicType)]@
 @(type_.typename)@
 @[  elif isinstance(type_, AbstractGenericString)]@
@@ -282,17 +278,16 @@ w@
 @[    end if]@
 string@
 @[    if type_.has_maximum_size()]@
-<@(type_.maximum_size)>@
+<=@(type_.maximum_size)@
 @[    end if]@
 @[  elif isinstance(type_, NamespacedType)]@
 @('/'.join([type_.namespaces[0], type_.name]))@
 @[  end if]@
-@# the suffix for nested types
-@[  if isinstance(member.type, AbstractSequence)]@
-@[    if isinstance(member.type, BoundedSequence)]@
-, @(member.type.maximum_size)@
-@[    end if]@
->@
+@# array/sequence suffix in .msg syntax
+@[  if isinstance(member.type, BoundedSequence)]@
+[<=@(member.type.maximum_size)]@
+@[  elif isinstance(member.type, UnboundedSequence)]@
+[]@
 @[  elif isinstance(member.type, Array)]@
 [@(member.type.size)]@
 @[  end if]@
diff --git a/rosidl_generator_py/test/test_interfaces.py b/rosidl_generator_py/test/test_interfaces.py
index 64225d9c..bcd30e8f 100644
--- a/rosidl_generator_py/test/test_interfaces.py
+++ b/rosidl_generator_py/test/test_interfaces.py
@@ -939,17 +939,17 @@ def test_string_slot_attributes() -> None:
     assert hasattr(msg, '__slots__')
     string_slot_types_dict = getattr(msg, 'get_fields_and_field_types')()
     expected_string_slot_types_dict = {
-        'ub_string_static_array_value': 'string<5>[3]',
-        'ub_string_ub_array_value': 'sequence<string<5>, 10>',
-        'ub_string_dynamic_array_value': 'sequence<string<5>>',
-        'string_dynamic_array_value': 'sequence<string>',
+        'ub_string_static_array_value': 'string<=5[3]',
+        'ub_string_ub_array_value': 'string<=5[<=10]',
+        'ub_string_dynamic_array_value': 'string<=5[]',
+        'string_dynamic_array_value': 'string[]',
         'string_static_array_value': 'string[3]',
-        'string_bounded_array_value': 'sequence<string, 10>',
-        'def_string_dynamic_array_value': 'sequence<string>',
+        'string_bounded_array_value': 'string[<=10]',
+        'def_string_dynamic_array_value': 'string[]',
         'def_string_static_array_value': 'string[3]',
-        'def_string_bounded_array_value': 'sequence<string, 10>',
-        'def_various_quotes': 'sequence<string>',
-        'def_various_commas': 'sequence<string>',
+        'def_string_bounded_array_value': 'string[<=10]',
+        'def_various_quotes': 'string[]',
+        'def_various_commas': 'string[]',
     }
 
     assert len(string_slot_types_dict) == len(expected_string_slot_types_dict)
@@ -1012,7 +1012,7 @@ def test_builtin_sequence_slot_attributes() -> None:
     assert hasattr(msg, '__slots__')
     builtin_sequence_slot_types_dict = getattr(msg, 'get_fields_and_field_types')()
     expected_builtin_sequence_slot_types_dict = {
-        'char_sequence_unbounded': 'sequence<char>',
+        'char_sequence_unbounded': 'char[]',
     }
 
     assert len(builtin_sequence_slot_types_dict) == len(expected_builtin_sequence_slot_types_dict)