diff --git a/cadCAD/configuration/__init__.py b/cadCAD/configuration/__init__.py
index 82d13d0..563a80f 100644
--- a/cadCAD/configuration/__init__.py
+++ b/cadCAD/configuration/__init__.py
@@ -22,6 +22,8 @@ class Configuration(object):
         self.policy_ops = policy_ops
         self.kwargs = kwargs
 
+        sanitize_config(self)
+
 
 def append_configs(sim_configs={}, initial_state={}, seeds={}, raw_exogenous_states={}, env_processes={}, partial_state_update_blocks={}, _exo_update_per_ts=True):
     if _exo_update_per_ts is True:
@@ -39,8 +41,7 @@ def append_configs(sim_configs={}, initial_state={}, seeds={}, raw_exogenous_sta
                 env_processes=env_processes,
                 partial_state_update_blocks=partial_state_update_blocks
             )
-            back_compatable_config = sanitize_config(config)
-            configs.append(back_compatable_config)
+            configs.append(config)
     elif isinstance(sim_configs, dict):
         config = Configuration(
             sim_config=sim_configs,
@@ -50,8 +51,7 @@ def append_configs(sim_configs={}, initial_state={}, seeds={}, raw_exogenous_sta
             env_processes=env_processes,
             partial_state_update_blocks=partial_state_update_blocks
         )
-        back_compatable_config = sanitize_config(config)
-        configs.append(back_compatable_config)
+        configs.append(config)
 
 
 class Identity:
@@ -124,7 +124,7 @@ class Processor:
             return sdf_values, bdf_values
 
         if len(partial_state_updates) != 0:
-            # backwards compatibility
+            # backwards compatibility # ToDo: Move this
             partial_state_updates = sanitize_partial_state_updates(partial_state_updates)
 
             bdf = self.create_matrix_field(partial_state_updates, 'policies')
diff --git a/cadCAD/configuration/utils/depreciationHandler.py b/cadCAD/configuration/utils/depreciationHandler.py
index 148163d..1f2862a 100644
--- a/cadCAD/configuration/utils/depreciationHandler.py
+++ b/cadCAD/configuration/utils/depreciationHandler.py
@@ -2,23 +2,19 @@ from copy import deepcopy
 
 
 def sanitize_config(config):
-    new_config = deepcopy(config)
     # for backwards compatibility, we accept old arguments via **kwargs
     # TODO: raise specific deprecation warnings for key == 'state_dict', key == 'seed', key == 'mechanisms'
-    for key, value in new_config.kwargs.items():
+    for key, value in config.kwargs.items():
         if key == 'state_dict':
-            new_config.initial_state = value
+            config.initial_state = value
         elif key == 'seed':
-            new_config.seeds = value
+            config.seeds = value
         elif key == 'mechanisms':
-            new_config.partial_state_updates = value
+            config.partial_state_updates = value
 
-    if new_config.initial_state == {}:
+    if config.initial_state == {}:
         raise Exception('The initial conditions of the system have not been set')
 
-    del config
-    return new_config
-
 
 def sanitize_partial_state_updates(partial_state_updates):
     new_partial_state_updates = deepcopy(partial_state_updates)
diff --git a/cadCAD/engine/__init__.py b/cadCAD/engine/__init__.py
index 5a1d4ad..e22b028 100644
--- a/cadCAD/engine/__init__.py
+++ b/cadCAD/engine/__init__.py
@@ -65,6 +65,7 @@ class Executor:
             config_idx += 1
 
         if self.exec_context == ExecutionMode.single_proc:
+            # ToDO: Deprication Handler - "sanitize" in appropriate place
             tensor_field = create_tensor_field(partial_state_updates.pop(), eps.pop())
             result = self.exec_method(simulation_execs, var_dict_list, states_lists, configs_structs, env_processes_list, Ts, Ns)
             return result, tensor_field