diff --git a/tests/test_script_annotations.py b/tests/test_script_annotations.py
index cd2f033f..028328af 100644
--- a/tests/test_script_annotations.py
+++ b/tests/test_script_annotations.py
@@ -7,6 +7,7 @@
 
 from hera.shared._pydantic import _PYDANTIC_VERSION
 from hera.workflows import Workflow, script
+from hera.workflows.io import Input
 from hera.workflows.parameter import Parameter
 from hera.workflows.steps import Steps
 
@@ -83,6 +84,30 @@ def echo_int(an_int: Annotated[int, Parameter(default=1)]):
     assert ("default cannot be set via the Parameter's default, use a Python default value instead") in str(e.value)
 
 
+def test_pydantic_input_with_default_throws_a_value_error(global_config_fixture):
+    """Test asserting that it is not possible to define default in the annotation in a Hera Input class."""
+
+    # GIVEN
+    global_config_fixture.experimental_features["script_pydantic_io"] = True
+
+    class ExampleInput(Input):
+        an_int: Annotated[int, Parameter(default=1)]
+
+    @script()
+    def echo_int(pydantic_input: ExampleInput):
+        print(pydantic_input.an_int)
+
+    global_config_fixture.experimental_features["script_annotations"] = True
+    with pytest.raises(ValueError) as e:
+        with Workflow(generate_name="test-default-", entrypoint="my-steps") as w:
+            with Steps(name="my-steps"):
+                echo_int()
+
+        w.to_dict()
+
+    assert ("default cannot be set via the Parameter's default, use a Python default value instead") in str(e.value)
+
+
 @pytest.mark.parametrize(
     "function_name,expected_input,expected_output",
     [