diff --git a/.github/workflows/pytest.yml b/.github/workflows/pytest.yml
index a5f03605b..24ee73cf7 100644
--- a/.github/workflows/pytest.yml
+++ b/.github/workflows/pytest.yml
@@ -21,7 +21,7 @@ jobs:
       uses: actions/checkout@main
       with:
         ref: main
-        fetch-depth: 0
+        # fetch-depth: 0
 
     - name: Set up Python
       uses: actions/setup-python@main
diff --git a/biosimulator_processes/steps/parameter_scan.py b/biosimulator_processes/steps/parameter_scan.py
index 0e593cd8a..8507c56dd 100644
--- a/biosimulator_processes/steps/parameter_scan.py
+++ b/biosimulator_processes/steps/parameter_scan.py
@@ -61,7 +61,9 @@ class DeterministicTimeCourseParameterScan(ParameterScan):
             used to run during update
     """
     config_schema = {
-        'process_config': TimeCourseProcessConfigSchema().model_dump(),
+        'process_config': {
+            '_default': TimeCourseProcessConfigSchema().model_dump(),
+            '_type': 'tree[string]'},
         'n_iterations': 'int',
         'iter_start': 'maybe[float]',
         'perturbation_magnitude': 'float',