diff --git a/pyproject.toml b/pyproject.toml
index a02ecbe..1037366 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,8 +1,8 @@
 [tool.poetry]
 name = "retrack"
-version = "2.5.0"
+version = "2.5.1"
 description = "A business rules engine"
-authors = ["Gabriel Guarisa <gabriel.guarisa@pier.digital>", "Nathalia Trotte <nathaliatrotte@gmail.com>"]
+authors = ["Gabriel Guarisa <gabriel.guarisa@pier.digital>"]
 license = "MIT"
 readme = "README.md"
 repository = "https://github.com/pier-digital/retrack"
diff --git a/retrack/nodes/base.py b/retrack/nodes/base.py
index 0ef84d2..680039f 100644
--- a/retrack/nodes/base.py
+++ b/retrack/nodes/base.py
@@ -44,6 +44,17 @@ def cast_int_to_str(v: typing.Any, info: pydantic.ValidationInfo) -> str:
 ]
 
 
+def cast_empty_string_to_none(v: str, info: pydantic.ValidationInfo) -> typing.Any:
+    if v == "":
+        return None
+    return v
+
+
+OptionalCastedToNoneStringType = typing.Annotated[
+    typing.Optional[str], pydantic.BeforeValidator(cast_empty_string_to_none)
+]
+
+
 class OutputConnectionItemModel(pydantic.BaseModel):
     node: CastedToStringType
     input_: str = pydantic.Field(alias="input")
diff --git a/retrack/nodes/inputs.py b/retrack/nodes/inputs.py
index 72db14f..e0db7ff 100644
--- a/retrack/nodes/inputs.py
+++ b/retrack/nodes/inputs.py
@@ -7,6 +7,7 @@
     InputConnectionModel,
     NodeKind,
     OutputConnectionModel,
+    OptionalCastedToNoneStringType,
 )
 
 ################################################
@@ -16,7 +17,7 @@
 
 class InputMetadataModel(pydantic.BaseModel):
     name: str
-    default: typing.Optional[str] = None
+    default: OptionalCastedToNoneStringType = None
 
 
 ################################################
diff --git a/retrack/nodes/outputs.py b/retrack/nodes/outputs.py
index 9aee712..5bf75dc 100644
--- a/retrack/nodes/outputs.py
+++ b/retrack/nodes/outputs.py
@@ -3,7 +3,12 @@
 import pandas as pd
 import pydantic
 
-from retrack.nodes.base import BaseNode, InputConnectionModel, NodeKind
+from retrack.nodes.base import (
+    BaseNode,
+    InputConnectionModel,
+    NodeKind,
+    OptionalCastedToNoneStringType,
+)
 from retrack.utils import constants
 
 ################################################
@@ -12,7 +17,7 @@
 
 
 class OutputMetadataModel(pydantic.BaseModel):
-    message: typing.Optional[str] = None
+    message: OptionalCastedToNoneStringType = None
 
 
 ################################################
diff --git a/tests/conftest.py b/tests/conftest.py
index 04827ad..c5e3d8e 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -1,7 +1,7 @@
 import pytest
 
 
-@pytest.fixture
+@pytest.fixture(scope="function")
 def valid_input_dict_before_validation() -> dict:
     return {
         "id": 1,
diff --git a/tests/test_nodes/test_input.py b/tests/test_nodes/test_input.py
index 7a44c38..d1a770c 100644
--- a/tests/test_nodes/test_input.py
+++ b/tests/test_nodes/test_input.py
@@ -7,3 +7,10 @@ def test_input_node(
     input_node = Input(**valid_input_dict_before_validation)
 
     assert input_node.model_dump(by_alias=True) == valid_input_dict_after_validation
+
+
+def test_input_with_empty_string_as_default(valid_input_dict_before_validation):
+    valid_input_dict_before_validation["data"]["default"] = ""
+    input_node = Input(**valid_input_dict_before_validation)
+
+    assert input_node.data.default is None