diff --git a/tests/flytekit/unit/core/test_imperative.py b/tests/flytekit/unit/core/test_imperative.py
index f120398306..2d34466862 100644
--- a/tests/flytekit/unit/core/test_imperative.py
+++ b/tests/flytekit/unit/core/test_imperative.py
@@ -212,6 +212,29 @@ def t2(a: typing.List[int]) -> int:
     assert wb() == [3, 6]
 
 
+def test_imperative_tuples():
+    @task
+    def t1() -> (int, str):
+        return 3, "three"
+
+    @task
+    def t3(a: int, b: str) -> typing.Tuple[int, str]:
+        return a + 2, "world" + b
+
+    wb = ImperativeWorkflow(name="my.workflow.a")
+    t1_node = wb.add_entity(t1)
+    t3_node = wb.add_entity(t3, a=t1_node.outputs["o0"], b=t1_node.outputs["o1"])
+    wb.add_workflow_output("wf0", t3_node.outputs["o0"], python_type=int)
+    wb.add_workflow_output("wf1", t3_node.outputs["o1"], python_type=str)
+    res = wb()
+    assert res == (5, "worldthree")
+
+    with pytest.raises(KeyError):
+        wb = ImperativeWorkflow(name="my.workflow.b")
+        t1_node = wb.add_entity(t1)
+        wb.add_entity(t3, a=t1_node.outputs["bad"], b=t1_node.outputs["o2"])
+
+
 def test_call_normal():
     @task
     def t1(a: int) -> (int, str):
diff --git a/tests/flytekit/unit/core/test_shim_task.py b/tests/flytekit/unit/core/test_shim_task.py
new file mode 100644
index 0000000000..b22f2e7349
--- /dev/null
+++ b/tests/flytekit/unit/core/test_shim_task.py
@@ -0,0 +1,63 @@
+import tempfile
+from collections import OrderedDict
+
+import mock
+
+from flytekit import ContainerTask, kwtypes
+from flytekit.core import context_manager
+from flytekit.core.context_manager import Image, ImageConfig
+from flytekit.core.python_customized_container_task import PythonCustomizedContainerTask, TaskTemplateResolver
+from flytekit.core.utils import write_proto_to_file
+from flytekit.tools.translator import get_serializable
+
+default_img = Image(name="default", fqn="test", tag="tag")
+serialization_settings = context_manager.SerializationSettings(
+    project="project",
+    domain="domain",
+    version="version",
+    env=None,
+    image_config=ImageConfig(default_image=default_img, images=[default_img]),
+)
+
+
+class Placeholder(object):
+    ...
+
+
+def test_resolver_load_task():
+    # any task is fine, just copied one
+    square = ContainerTask(
+        name="square",
+        input_data_dir="/var/inputs",
+        output_data_dir="/var/outputs",
+        inputs=kwtypes(val=int),
+        outputs=kwtypes(out=int),
+        image="alpine",
+        command=["sh", "-c", "echo $(( {{.Inputs.val}} * {{.Inputs.val}} )) | tee /var/outputs/out"],
+    )
+
+    resolver = TaskTemplateResolver()
+    ts = get_serializable(OrderedDict(), serialization_settings, square)
+    with tempfile.NamedTemporaryFile() as f:
+        write_proto_to_file(ts.template.to_flyte_idl(), f.name)
+        # load_task should create an instance of the path to the object given, doesn't need to be a real executor
+        shim_task = resolver.load_task([f.name, f"{Placeholder.__module__}.Placeholder"])
+        assert isinstance(shim_task.executor, Placeholder)
+        assert shim_task.task_template.id.name == "square"
+        assert shim_task.task_template.interface.inputs["val"] is not None
+        assert shim_task.task_template.interface.outputs["out"] is not None
+
+
+@mock.patch("flytekit.core.python_customized_container_task.PythonCustomizedContainerTask.get_config")
+@mock.patch("flytekit.core.python_customized_container_task.PythonCustomizedContainerTask.get_custom")
+def test_serialize_to_model(mock_custom, mock_config):
+    mock_custom.return_value = {"a": "custom"}
+    mock_config.return_value = {"a": "config"}
+    ct = PythonCustomizedContainerTask(
+        name="mytest", task_config=None, container_image="someimage", executor_type=Placeholder
+    )
+    tt = ct.serialize_to_model(serialization_settings)
+    assert tt.container.image == "someimage"
+    assert len(tt.config) == 1
+    assert tt.id.name == "mytest"
+    assert len(tt.custom) == 1