diff --git a/docs/release-notes.md b/docs/release-notes.md
index 14254b3..3887fce 100644
--- a/docs/release-notes.md
+++ b/docs/release-notes.md
@@ -12,6 +12,20 @@ hide:
[//]: # (--------------------------------------------------------------------------------------------------------------)
+## [v0.1.3](https://github.com/dapensoft/pyorlib/releases/tag/0.1.3) July 30, 2025 { id="0.1.3" }
+
+
+
+##### Changed
+
+- Updated the lower bound variable definition in `pulp_engine` to set it to `None` when `-inf` is specified as the lower bound.
+
+##### Fixed
+
+- Updated deprecated `_pytest.python_api.raises` imports in several tests.
+
+[//]: # (--------------------------------------------------------------------------------------------------------------)
+
## [v0.1.2](https://github.com/dapensoft/pyorlib/releases/tag/0.1.2) April 9, 2024 { id="0.1.2" }
diff --git a/src/pyorlib/__init__.py b/src/pyorlib/__init__.py
index ab5a43d..861d3e4 100644
--- a/src/pyorlib/__init__.py
+++ b/src/pyorlib/__init__.py
@@ -3,7 +3,7 @@
mathematical models in a standardized manner across different optimization packages.
"""
-__version__ = "0.1.2"
+__version__ = "0.1.3"
from .engines import Engine
from .model import Model
diff --git a/src/pyorlib/engines/pulp/pulp_engine.py b/src/pyorlib/engines/pulp/pulp_engine.py
index a6117ed..b23101c 100644
--- a/src/pyorlib/engines/pulp/pulp_engine.py
+++ b/src/pyorlib/engines/pulp/pulp_engine.py
@@ -100,14 +100,14 @@ def __init__(
pulp_var = LpVariable(
name=name,
cat=LpInteger,
- lowBound=lower_bound,
+ lowBound=lower_bound if lower_bound > -inf else None,
upBound=upper_bound if upper_bound < inf else None,
)
elif self.value_type == ValueType.CONTINUOUS:
pulp_var = LpVariable(
name=name,
cat=LpContinuous,
- lowBound=lower_bound,
+ lowBound=lower_bound if lower_bound > -inf else None,
upBound=upper_bound if upper_bound < inf else None,
)
else:
diff --git a/tests/algebra/expressions/test_expression.py b/tests/algebra/expressions/test_expression.py
index eb37d7e..1857533 100644
--- a/tests/algebra/expressions/test_expression.py
+++ b/tests/algebra/expressions/test_expression.py
@@ -1,6 +1,6 @@
from math import isclose
-from _pytest.python_api import raises
+from pytest import raises
from pyorlib.algebra import Element, Expression
diff --git a/tests/algebra/terms/constants/test_constant.py b/tests/algebra/terms/constants/test_constant.py
index 44be24b..8b22251 100644
--- a/tests/algebra/terms/constants/test_constant.py
+++ b/tests/algebra/terms/constants/test_constant.py
@@ -1,6 +1,6 @@
from math import inf
-from _pytest.python_api import raises
+from pytest import raises
from pyorlib.algebra import Term, Constant
from pyorlib.enums import ValueType, TermType
diff --git a/tests/algebra/terms/test_term.py b/tests/algebra/terms/test_term.py
index 1c95fce..b5df316 100644
--- a/tests/algebra/terms/test_term.py
+++ b/tests/algebra/terms/test_term.py
@@ -1,7 +1,7 @@
from math import isclose
from typing import Any
-from _pytest.python_api import raises
+from pytest import raises
from pyorlib.algebra import Element, Expression, Term, Constant
from pyorlib.enums import ValueType
diff --git a/tests/algebra/terms/variables/test_variable.py b/tests/algebra/terms/variables/test_variable.py
index 81e1df8..605aae7 100644
--- a/tests/algebra/terms/variables/test_variable.py
+++ b/tests/algebra/terms/variables/test_variable.py
@@ -1,6 +1,6 @@
from math import inf
-from _pytest.python_api import raises
+from pytest import raises
from pyorlib.algebra import Term, Variable
from pyorlib.engines import Engine
diff --git a/tests/model/test_model.py b/tests/model/test_model.py
index 2a3ad9f..83c1d1a 100644
--- a/tests/model/test_model.py
+++ b/tests/model/test_model.py
@@ -1,7 +1,7 @@
from math import inf
from typing import List
-from _pytest.python_api import raises
+from pytest import raises
from pyorlib import Model, Engine
from pyorlib.algebra import Term, Element
diff --git a/tests/structures/parameters/test_multi_value_parameter.py b/tests/structures/parameters/test_multi_value_parameter.py
index 826e73a..ecd0319 100644
--- a/tests/structures/parameters/test_multi_value_parameter.py
+++ b/tests/structures/parameters/test_multi_value_parameter.py
@@ -1,6 +1,6 @@
from math import inf
-from _pytest.python_api import raises
+from pytest import raises
from pyorlib.enums import ParameterType, ValueType
from pyorlib.structures import MultiValueParameter, Parameter
diff --git a/tests/structures/parameters/test_single_value_parameter.py b/tests/structures/parameters/test_single_value_parameter.py
index ab7ce60..2597af8 100644
--- a/tests/structures/parameters/test_single_value_parameter.py
+++ b/tests/structures/parameters/test_single_value_parameter.py
@@ -1,6 +1,6 @@
from math import inf
-from _pytest.python_api import raises
+from pytest import raises
from pyorlib.enums import ParameterType, ValueType
from pyorlib.structures import SingleValueParameter, Parameter
diff --git a/tests/validators/fields/test_dimension_field.py b/tests/validators/fields/test_dimension_field.py
index 3160d2d..3ce2147 100644
--- a/tests/validators/fields/test_dimension_field.py
+++ b/tests/validators/fields/test_dimension_field.py
@@ -1,6 +1,6 @@
from dataclasses import dataclass
-from _pytest.python_api import raises
+from pytest import raises
from pyorlib.validators import DimensionField
diff --git a/tests/validators/fields/test_parameter_field.py b/tests/validators/fields/test_parameter_field.py
index 3d62585..8f9c46f 100644
--- a/tests/validators/fields/test_parameter_field.py
+++ b/tests/validators/fields/test_parameter_field.py
@@ -1,6 +1,6 @@
from dataclasses import dataclass
-from _pytest.python_api import raises
+from pytest import raises
from pyorlib.enums import ParameterType, ValueType
from pyorlib.structures import SingleValueParameter, MultiValueParameter