diff --git a/tests/fixtures.py b/tests/fixtures.py
index c068bd62..a51373ba 100644
--- a/tests/fixtures.py
+++ b/tests/fixtures.py
@@ -129,7 +129,7 @@ def __init__(
     "bounds_interventions": [[0.0, 0.1], [40.0, 0.5]],
 }
 
-# Creating a combined intervention
+# Creating a combined interventions by combining into list of Callables
 intervened_params = ["beta_c", "gamma"]
 static_parameter_interventions1 = param_value_objective(
     param_name=[intervened_params[0]],
@@ -139,15 +139,13 @@ def __init__(
     param_name=[intervened_params[1]],
     param_value=torch.tensor([0.45]),
 )
-# Combine different intervention templates into a list of Callables
-static_parameter_interventions = lambda x: [
-    static_parameter_interventions1(torch.atleast_1d(x[0])),
-    static_parameter_interventions2(torch.atleast_1d(x[1])),
-]
 optkwargs_SEIRHD_paramtimeComb_maxQoI = {
     "qoi": lambda x: obs_max_qoi(x, ["I_state"]),
     "risk_bound": 3e5,
-    "static_parameter_interventions": static_parameter_interventions,
+    "static_parameter_interventions": lambda x: [
+        static_parameter_interventions1(torch.atleast_1d(x[0])),
+        static_parameter_interventions2(torch.atleast_1d(x[1])),
+    ],
     "objfun": lambda x: np.abs(0.35 - x[0]) - x[1],
     "initial_guess_interventions": [0.35, 5.0],
     "bounds_interventions": [[0.1, 1.0], [0.5, 90.0]],
diff --git a/tests/test_interfaces.py b/tests/test_interfaces.py
index 4b58a571..7e647c5b 100644
--- a/tests/test_interfaces.py
+++ b/tests/test_interfaces.py
@@ -584,12 +584,18 @@ def test_optimize(model_fixture, start_time, end_time, num_samples):
         assert opt_policy[i] <= bounds_interventions[1][i]
 
     if "fixed_static_parameter_interventions" in optimize_kwargs:
-        opt_intervention = combine_static_parameter_interventions(
-            [
-                deepcopy(optimize_kwargs["fixed_static_parameter_interventions"]),
+        intervention_list = [
+            deepcopy(optimize_kwargs["fixed_static_parameter_interventions"])
+        ]
+        intervention_list.extend(
+            [optimize_kwargs["static_parameter_interventions"](opt_result["policy"])]
+            if not isinstance(
                 optimize_kwargs["static_parameter_interventions"](opt_result["policy"]),
-            ]
+                list,
+            )
+            else optimize_kwargs["static_parameter_interventions"](opt_result["policy"])
         )
+        opt_intervention = combine_static_parameter_interventions(intervention_list)
     else:
         opt_intervention = optimize_kwargs["static_parameter_interventions"](
             opt_result["policy"]