diff --git a/src/_nebari/stages/terraform_state/__init__.py b/src/_nebari/stages/terraform_state/__init__.py
index 37568be13..edee2db71 100644
--- a/src/_nebari/stages/terraform_state/__init__.py
+++ b/src/_nebari/stages/terraform_state/__init__.py
@@ -260,7 +260,7 @@ def check_immutable_fields(self):
 
         # compute diff of remote/prior and current nebari config
         nebari_config_diff = utils.JsonDiff(
-            nebari_config_state.model_dump(), self.config.model_dump()
+            nebari_config_state, self.config.model_dump()
         )
         # check if any changed fields are immutable
         for keys, old, new in nebari_config_diff.modified():
@@ -284,7 +284,7 @@ def check_immutable_fields(self):
                     f'Attempting to change immutable field "{key_path}" ("{old}"->"{new}") in Nebari config file.  Immutable fields cannot be changed after initial deployment.'
                 )
 
-    def get_nebari_config_state(self):
+    def get_nebari_config_state(self) -> dict:
         directory = str(self.output_directory / self.stage_prefix)
         tf_state = terraform.show(directory)
         nebari_config_state = None
@@ -294,11 +294,7 @@ def get_nebari_config_state(self):
             tf_state.get("values", {}).get("root_module", {}).get("resources", [])
         ):
             if resource["address"] == "terraform_data.nebari_config":
-                from nebari.plugins import nebari_plugin_manager
-
-                nebari_config_state = nebari_plugin_manager.config_schema(
-                    **resource["values"]["input"]
-                )
+                nebari_config_state = resource["values"]["input"]
                 break
         return nebari_config_state
 
diff --git a/tests/tests_unit/test_stages.py b/tests/tests_unit/test_stages.py
index 8c0facf8c..74e6d3f3d 100644
--- a/tests/tests_unit/test_stages.py
+++ b/tests/tests_unit/test_stages.py
@@ -29,7 +29,7 @@ def terraform_state_stage(mock_config, tmp_path):
 
 @patch.object(TerraformStateStage, "get_nebari_config_state")
 def test_check_immutable_fields_no_changes(mock_get_state, terraform_state_stage):
-    mock_get_state.return_value = terraform_state_stage.config
+    mock_get_state.return_value = terraform_state_stage.config.model_dump()
 
     # This should not raise an exception
     terraform_state_stage.check_immutable_fields()
@@ -41,7 +41,7 @@ def test_check_immutable_fields_mutable_change(
 ):
     old_config = mock_config.model_copy(deep=True)
     old_config.namespace = "old-namespace"
-    mock_get_state.return_value = old_config
+    mock_get_state.return_value = old_config.model_dump()
 
     # This should not raise an exception (namespace is mutable)
     terraform_state_stage.check_immutable_fields()
@@ -54,7 +54,7 @@ def test_check_immutable_fields_immutable_change(
 ):
     old_config = mock_config.model_copy(deep=True)
     old_config.provider = schema.ProviderEnum.gcp
-    mock_get_state.return_value = old_config
+    mock_get_state.return_value = old_config.model_dump()
 
     # Mock the provider field to be immutable
     mock_model_fields.__getitem__.return_value.json_schema_extra = {"immutable": True}
@@ -77,7 +77,7 @@ def test_check_immutable_fields_no_prior_state(mock_get_state, terraform_state_s
 def test_check_dict_value_change(mock_get_state, terraform_state_stage, mock_config):
     old_config = mock_config.model_copy(deep=True)
     terraform_state_stage.config.local.node_selectors["worker"].value += "new_value"
-    mock_get_state.return_value = old_config
+    mock_get_state.return_value = old_config.model_dump()
 
     # should not throw an exception
     terraform_state_stage.check_immutable_fields()
@@ -87,7 +87,19 @@ def test_check_dict_value_change(mock_get_state, terraform_state_stage, mock_con
 def test_check_list_change(mock_get_state, terraform_state_stage, mock_config):
     old_config = mock_config.model_copy(deep=True)
     old_config.environments["environment-dask.yaml"].channels.append("defaults")
-    mock_get_state.return_value = old_config
+    mock_get_state.return_value = old_config.model_dump()
 
     # should not throw an exception
     terraform_state_stage.check_immutable_fields()
+
+
+@patch.object(TerraformStateStage, "get_nebari_config_state")
+def test_check_immutable_fields_old_nebari_version(
+    mock_get_state, terraform_state_stage, mock_config
+):
+    old_config = mock_config.model_copy(deep=True).model_dump()
+    old_config["nebari_version"] = "2024.7.1"  # Simulate an old version
+    mock_get_state.return_value = old_config
+
+    # This should not raise an exception
+    terraform_state_stage.check_immutable_fields()