diff --git a/test_launch_ros/test/rostest/composition.test.py b/test_launch_ros/test/rostest/composition.test.py
index 4e15e9bb..992cfe21 100644
--- a/test_launch_ros/test/rostest/composition.test.py
+++ b/test_launch_ros/test/rostest/composition.test.py
@@ -77,25 +77,24 @@ def generate_test_description(ready_fn):
 
     launch_description.add_action(get_default_launch_description())
     launch_description.add_action(mock_container)
-    # TODO(sloretz) post-launch composable node actions
-    # launch_description.add_action(
-    #     RegisterEventHandler(
-    #         event_handler=OnProcessStart(
-    #             target_action=mock_container,
-    #             on_start=[
-    #                 LoadComposableNodes(
-    #                     composable_node_descriptions=[
-    #                         ComposableNode(
-    #                             package='fake_package', node_plugin='node_name',
-    #                             node_name='my_talker'
-    #                         ),
-    #                     ],
-    #                     target_container=mock_container
-    #                 )
-    #             ]
-    #         )
-    #     )
-    # )
+    launch_description.add_action(
+        RegisterEventHandler(
+            event_handler=OnProcessStart(
+                target_action=mock_container,
+                on_start=[
+                    LoadComposableNodes(
+                        composable_node_descriptions=[
+                            ComposableNode(
+                                package='fake_package', node_plugin='node_name_on_event',
+                                node_name='my_talker_on_event'
+                            ),
+                        ],
+                        target_container=mock_container
+                    )
+                ]
+            )
+        )
+    )
     launch_description.add_action(
         OpaqueFunction(function=lambda context: ready_fn())
     )
@@ -124,6 +123,13 @@ def test_custom_node_name(self, container):
         request.node_name = 'my_talker'
         self.proc_output.assertWaitFor(expected_output=repr(request), process=container)
 
+    def test_custom_node_name_post_launch(self, container):
+        request = LoadNode.Request()
+        request.package_name = 'fake_package'
+        request.plugin_name = 'node_name_on_event'
+        request.node_name = 'my_talker_on_event'
+        self.proc_output.assertWaitFor(expected_output=repr(request), process=container)
+
     def test_custom_node_namespace(self, container):
         request = LoadNode.Request()
         request.package_name = 'fake_package'
diff --git a/test_launch_ros/test_launch_ros/mock_composable_container.py b/test_launch_ros/test_launch_ros/mock_composable_container.py
index ea003fd8..5a280e34 100644
--- a/test_launch_ros/test_launch_ros/mock_composable_container.py
+++ b/test_launch_ros/test_launch_ros/mock_composable_container.py
@@ -79,6 +79,11 @@ def __init__(self, name, namespace):
         extra_arguments.full_node_name = '/a_nodename'
         extra_arguments.unique_id = 128
 
+        node_name_on_event = LoadNode.Response()
+        node_name_on_event.success = True
+        node_name_on_event.full_node_name = '/my_talker_on_event'
+        node_name_on_event.unique_id = 256
+
         self.__load_node_responses = {
             ('fake_package', 'fail_to_load'): fail_to_load,
             ('fake_package', 'successfully_load'): successfully_load,
@@ -88,6 +93,7 @@ def __init__(self, name, namespace):
             ('fake_package', 'remap_rules'): remap_rules,
             ('fake_package', 'parameters'): parameters,
             ('fake_package', 'extra_arguments'): extra_arguments,
+            ('fake_package', 'node_name_on_event'): node_name_on_event,
         }
 
         self.unexpected_request = False