diff --git a/docs/examples/workflows/experimental/script_pydantic_io.md b/docs/examples/workflows/experimental/script_pydantic_io.md
index f26f7e7c4..fbca1c029 100644
--- a/docs/examples/workflows/experimental/script_pydantic_io.md
+++ b/docs/examples/workflows/experimental/script_pydantic_io.md
@@ -8,6 +8,11 @@
 === "Hera"
 
     ```python linenums="1"
+    try:
+        from pydantic.v1 import BaseModel
+    except ImportError:
+        from pydantic import BaseModel
+
     from hera.shared import global_config
     from hera.workflows import Artifact, ArtifactLoader, Parameter, Workflow, script
     from hera.workflows.io import RunnerInput, RunnerOutput
@@ -20,9 +25,13 @@
     global_config.experimental_features["script_annotations"] = True
     global_config.experimental_features["script_pydantic_io"] = True
 
+    class MyObject(BaseModel):
+        a_dict: dict = {}
+        a_str: str = "a default string"
 
     class MyInput(RunnerInput):
         param_int: Annotated[int, Parameter(name="param-input")] = 42
+        an_object: Annotated[MyObject, Parameter(name="obj-input")] = MyObject(a_dict={"my-key": "a-value"}, a_str="hello world!")
         artifact_int: Annotated[int, Artifact(name="artifact-input", loader=ArtifactLoader.json)]
 
 
@@ -58,6 +67,8 @@
           parameters:
           - default: '42'
             name: param-input
+          - default: '{"a_dict": {"my-key": "a-value"}, "a_str": "hello world!"}'
+            name: obj-input
         name: pydantic-io
         outputs:
           artifacts:
diff --git a/examples/workflows/experimental/script-pydantic-io.yaml b/examples/workflows/experimental/script-pydantic-io.yaml
index 54a6fe892..55256a985 100644
--- a/examples/workflows/experimental/script-pydantic-io.yaml
+++ b/examples/workflows/experimental/script-pydantic-io.yaml
@@ -11,6 +11,8 @@ spec:
       parameters:
       - default: '42'
         name: param-input
+      - default: '{"a_dict": {"my-key": "a-value"}, "a_str": "hello world!"}'
+        name: obj-input
     name: pydantic-io
     outputs:
       artifacts:
diff --git a/examples/workflows/experimental/script_pydantic_io.py b/examples/workflows/experimental/script_pydantic_io.py
index 79406753a..625809a3a 100644
--- a/examples/workflows/experimental/script_pydantic_io.py
+++ b/examples/workflows/experimental/script_pydantic_io.py
@@ -1,3 +1,8 @@
+try:
+    from pydantic.v1 import BaseModel
+except ImportError:
+    from pydantic import BaseModel
+
 from hera.shared import global_config
 from hera.workflows import Artifact, ArtifactLoader, Parameter, Workflow, script
 from hera.workflows.io import RunnerInput, RunnerOutput
@@ -10,9 +15,13 @@
 global_config.experimental_features["script_annotations"] = True
 global_config.experimental_features["script_pydantic_io"] = True
 
+class MyObject(BaseModel):
+    a_dict: dict = {}
+    a_str: str = "a default string"
 
 class MyInput(RunnerInput):
     param_int: Annotated[int, Parameter(name="param-input")] = 42
+    an_object: Annotated[MyObject, Parameter(name="obj-input")] = MyObject(a_dict={"my-key": "a-value"}, a_str="hello world!")
     artifact_int: Annotated[int, Artifact(name="artifact-input", loader=ArtifactLoader.json)]
 
 
diff --git a/src/hera/workflows/io.py b/src/hera/workflows/io.py
index 020c40e01..24709920f 100644
--- a/src/hera/workflows/io.py
+++ b/src/hera/workflows/io.py
@@ -3,6 +3,7 @@
 from typing import Any, List, Union
 
 from hera.shared._pydantic import BaseModel
+from hera.shared.serialization import serialize
 from hera.workflows.artifact import Artifact
 from hera.workflows.parameter import Parameter
 
@@ -30,7 +31,8 @@ def _get_parameters(cls) -> List[Parameter]:
                 if isinstance(get_args(annotations[field])[1], Parameter):
                     param = get_args(annotations[field])[1]
                     if cls.__fields__[field].default:
-                        param.default = cls.__fields__[field].default
+                        # Serialize the value (usually done in Parameter's validator)
+                        param.default = serialize(cls.__fields__[field].default)
                     parameters.append(param)
             else:
                 # Create a Parameter from basic type annotations