diff --git a/tests/unit/core/python/arguments/test_PythonFunctionArgument.py b/tests/unit/core/python/arguments/test_PythonFunctionArgument.py
index 4b17f2d..f128d40 100644
--- a/tests/unit/core/python/arguments/test_PythonFunctionArgument.py
+++ b/tests/unit/core/python/arguments/test_PythonFunctionArgument.py
@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from src.jcloud_docsgen.core.python.arguments import PythonFunctionArgument, PythonArgumentKind, PythonFunctionArgumentDefault
+from src.jcloud_docsgen.core.python.arguments import PythonFunctionArgument, PythonArgumentKind
 from src.jcloud_docsgen.exceptions import InvalidPythonIdentifierError, InvalidPythonAnnotationError
 import ast
 import pytest
@@ -23,7 +23,7 @@ import pytest
     (42, PythonArgumentKind.NORMAL, None, None, TypeError, 'expected \'str\', got \'int\''),
     (4.2, PythonArgumentKind.NORMAL, None, None, TypeError, 'expected \'str\', got \'float\''),
     (4.2, PythonArgumentKind.NORMAL, None, None, TypeError, 'expected \'str\', got \'float\''),
-    ('a', PythonArgumentKind.NORMAL, 1, None, TypeError, 'expected either \'PythonFunctionArgumentDefault\' or \'NoneType\', got \'int\''),
+    ('a', PythonArgumentKind.NORMAL, 1, None, TypeError, 'expected either \'str\' or \'NoneType\', got \'int\''),
     ('a', PythonArgumentKind.NORMAL, None, 1, TypeError, 'expected either \'str\' or \'NoneType\', got \'int\''),
     ('a', 0, None, None, TypeError, 'expected \'PythonArgumentKind\', got \'int\''),
     ('a', PythonArgumentKind.NORMAL, None, '', InvalidPythonAnnotationError, 'invalid annotation'),
@@ -89,9 +89,9 @@ def test_PythonFunctionArgument_exceptions(name, kind, default, annotation, expe
 ])
 @pytest.mark.parametrize('default', [
     None,
-    PythonFunctionArgumentDefault(ast.Constant(value = 'x')),
-    PythonFunctionArgumentDefault(ast.Constant(value = 1)),
-    PythonFunctionArgumentDefault(ast.Constant(value = None)),
+    'x',
+    '1',
+    None,
 ])
 @pytest.mark.parametrize('annotation', [
     None,