diff --git a/launch/launch/actions/group_action.py b/launch/launch/actions/group_action.py
index e67ac0876..b81a8b4d5 100644
--- a/launch/launch/actions/group_action.py
+++ b/launch/launch/actions/group_action.py
@@ -93,8 +93,10 @@ def parse(cls, entity: Entity, parser: Parser
               ) -> Tuple[Type['GroupAction'], Dict[str, Any]]:
         """Return `GroupAction` action and kwargs for constructing it."""
         _, kwargs = super().parse(entity, parser)
-        scoped = entity.get_attr('scoped', data_type=bool, optional=True)
-        forwarding = entity.get_attr('forwarding', data_type=bool, optional=True)
+        scoped = entity.get_attr(
+            'scoped', data_type=bool, optional=True, can_be_str=False)
+        forwarding = entity.get_attr(
+            'forwarding', data_type=bool, optional=True, can_be_str=False)
         keeps = entity.get_attr('keep', data_type=List[Entity], optional=True)
         if scoped is not None:
             kwargs['scoped'] = scoped
diff --git a/launch_xml/test/launch_xml/test_group.py b/launch_xml/test/launch_xml/test_group.py
index 1a7217847..d281f3bc5 100644
--- a/launch_xml/test/launch_xml/test_group.py
+++ b/launch_xml/test/launch_xml/test_group.py
@@ -26,8 +26,8 @@
 from launch.actions import ResetLaunchConfigurations
 from launch.actions import SetLaunchConfiguration
 from launch.launch_context import LaunchContext
-
 from parser_no_extensions import load_no_extensions
+import pytest
 
 
 def test_group():
@@ -86,5 +86,14 @@ def test_group():
     actions[7].visit(lc)
 
 
+@pytest.mark.parametrize('attribute', ('scoped', 'forwarding'))
+def test_group_rejects_invalid_boolean_attributes(attribute):
+    xml_file = f'<launch><group {attribute}="invalid"/></launch>'
+    root_entity, parser = load_no_extensions(io.StringIO(xml_file))
+
+    with pytest.raises(TypeError, match=f"Attribute '{attribute}'"):
+        parser.parse_description(root_entity)
+
+
 if __name__ == '__main__':
     test_group()
diff --git a/launch_yaml/test/launch_yaml/test_group.py b/launch_yaml/test/launch_yaml/test_group.py
index 76c087ab7..14a926ba6 100644
--- a/launch_yaml/test/launch_yaml/test_group.py
+++ b/launch_yaml/test/launch_yaml/test_group.py
@@ -28,6 +28,7 @@
 from launch.launch_context import LaunchContext
 
 from parser_no_extensions import load_no_extensions
+import pytest
 
 
 def test_group():
@@ -98,5 +99,19 @@ def test_group():
     actions[7].visit(lc)
 
 
+@pytest.mark.parametrize('attribute', ('scoped', 'forwarding'))
+def test_group_rejects_invalid_boolean_attributes(attribute):
+    yaml_file = f"""\
+    launch:
+    -   group:
+            {attribute}: invalid
+    """
+    yaml_file = textwrap.dedent(yaml_file)
+    root_entity, parser = load_no_extensions(io.StringIO(yaml_file))
+
+    with pytest.raises(TypeError, match=f"Attribute '{attribute}'"):
+        parser.parse_description(root_entity)
+
+
 if __name__ == '__main__':
     test_group()