diff --git a/pybop/models/empirical/base_ecm.py b/pybop/models/empirical/base_ecm.py
index 8d0c72d1..f52c6035 100644
--- a/pybop/models/empirical/base_ecm.py
+++ b/pybop/models/empirical/base_ecm.py
@@ -66,8 +66,9 @@ def __init__(
         super().__init__(name=name, parameter_set=parameter_set)
 
         # Set parameters, using either the provided ones or the default
+        self.default_parameter_values = self.pybamm_model.default_parameter_values
         self._parameter_set = (
-            self._parameter_set or self.pybamm_model.default_parameter_values.copy()
+            self._parameter_set or self.default_parameter_values.copy()
         )
 
         # Define model geometry and discretization
diff --git a/pybop/models/lithium_ion/base_echem.py b/pybop/models/lithium_ion/base_echem.py
index b28a363f..80b1c28d 100644
--- a/pybop/models/lithium_ion/base_echem.py
+++ b/pybop/models/lithium_ion/base_echem.py
@@ -57,8 +57,9 @@ def __init__(
         self._unprocessed_model = self.pybamm_model
 
         # Set parameters, using either the provided ones or the default
+        self.default_parameter_values = self.pybamm_model.default_parameter_values
         self._parameter_set = (
-            self._parameter_set or self.pybamm_model.default_parameter_values.copy()
+            self._parameter_set or self.default_parameter_values.copy()
         )
 
         # Define model geometry and discretization