diff --git a/muto_composer/plugins/launch_plugin.py b/muto_composer/plugins/launch_plugin.py
index 55ccccb..8687f73 100644
--- a/muto_composer/plugins/launch_plugin.py
+++ b/muto_composer/plugins/launch_plugin.py
@@ -126,8 +126,12 @@ def source_workspaces(self, current: StackManifest):
             self.get_logger().error("Failed to parse source data as JSON.")
             return
 
-        # Get stack name - check metadata.name first, then name, then default
-        stack_name = self._get_stack_name(current)
+        # Get stack name - handle both dict and StackManifest msg objects
+        if isinstance(current, dict):
+            stack_name = self._get_stack_name(current)
+        else:
+            # StackManifest msg: use .name attribute directly
+            stack_name = getattr(current, "name", None) or "default"
         workspace_dir = os.path.join(WORKSPACES_PATH, stack_name.replace(" ", "_"))
 
         def source_script(name: str, script_path: str) -> None:
@@ -390,8 +394,14 @@ def _launch_via_ros2_launch(self, context: StackContext, full_path: str, launch_
             launch_file: Original launch file name (for tracking)
         """
         # Source the workspace before launching
-        working_dir = os.path.dirname(os.path.dirname(full_path))
-        setup_bash = os.path.join(working_dir, "install", "setup.bash")
+        # Use context.workspace_path (the actual colcon workspace root) rather than
+        # deriving from the launch file path, which breaks for nested package structures.
+        workspace_dir = (
+            context.workspace_path
+            if context and context.workspace_path
+            else os.path.dirname(os.path.dirname(full_path))
+        )
+        setup_bash = os.path.join(workspace_dir, "install", "setup.bash")
         if os.path.exists(setup_bash):
             self._source_workspace(setup_bash)
 
diff --git a/test/test_launch_plugin.py b/test/test_launch_plugin.py
index 13c5a99..236fc1a 100644
--- a/test/test_launch_plugin.py
+++ b/test/test_launch_plugin.py
@@ -160,6 +160,7 @@ def test_source_workspaces_no_current_stack(self, mock_environ_update, mock_subp
     @patch("os.environ.update")
     def test_source_workspace(self, mock_environ_update, mock_subprocess_run, mock_get_path):
         mock_current = MagicMock()
+        mock_current.name = "Test Stack"
         mock_current.source = json.dumps({"workspace_name": "/mock/file"})
         # Mock the _get_stack_name method
         with patch.object(self.node, "_get_stack_name", return_value="Test Stack"), patch(