diff --git a/src/marqo/tensor_search/models/index_settings.py b/src/marqo/tensor_search/models/index_settings.py
index 4a975afd7..1012b6d48 100644
--- a/src/marqo/tensor_search/models/index_settings.py
+++ b/src/marqo/tensor_search/models/index_settings.py
@@ -1,5 +1,5 @@
 import time
-from typing import Dict, Any, Optional, List
+from typing import Dict, Any, Optional, List, Union
 
 from pydantic import root_validator
 
@@ -45,15 +45,19 @@ class IndexSettings(StrictBaseModel):
     @root_validator(pre=True)
     def validate_field_names(cls, values):
         # Verify no snake case field names (pydantic won't catch these due to allow_population_by_field_name = True)
-        def validate_dict_keys(d: dict):
-            for key in d.keys():
-                if '_' in key:
-                    raise ValueError(f"Invalid field name '{key}'. "
-                                     f"See Create Index API reference here https://docs.marqo.ai/2.0.0/API-Reference/Indexes/create_index/")
-                if isinstance(d[key], dict):
-                    validate_dict_keys(d[key])
-
-        validate_dict_keys(values)
+        def validate_keys(d: Union[dict, list]):
+            if isinstance(d, dict):
+                for key in d.keys():
+                    if '_' in key:
+                        raise ValueError(f"Invalid field name '{key}'. "
+                                         f"See Create Index API reference here https://docs.marqo.ai/2.0.0/API-Reference/Indexes/create_index/")
+                    
+                    validate_keys(d[key])
+            elif isinstance(d, list):
+                for item in d:
+                    validate_keys(item)
+
+        validate_keys(values)
 
         return values
 
diff --git a/tests/tensor_search/test_api.py b/tests/tensor_search/test_api.py
index 0f1b43890..67b0bafd0 100644
--- a/tests/tensor_search/test_api.py
+++ b/tests/tensor_search/test_api.py
@@ -145,23 +145,54 @@ def test_invalid_argument_error(self):
         assert "Could not find model properties for" in response.json()["message"]
 
     def test_create_index_snake_case_fails(self):
-        # Verify snake case rejected for fields that have camel case as alias
-        response = self.client.post(
-            "/indexes/my_index",
-            json={
-                "type": "structured",
-                "allFields": [{"name": "field1", "type": "text"}],
-                "tensorFields": [],
-                'annParameters': {
-                    'spaceType': 'dotproduct',
-                    'parameters': {
-                        'ef_construction': 128,
-                        'm': 16
-                    }
-                }
-            }
-        )
-
-        self.assertEqual(response.status_code, 422)
-        self.assertTrue("Invalid field name 'ef_construction'" in response.text)
-
+        """
+        Verify snake case rejected for fields that have camel case as alias
+        """
+        test_cases = [
+            ({
+                 "type": "structured",
+                 "allFields": [
+                     {
+                         "name": "field1",
+                         "type": "text"
+                     },
+                     {
+                         "name": "field2",
+                         "type": "multimodal_combination",
+                         "dependent_fields": ["field1"]
+                     }
+                 ],
+                 "tensorFields": [],
+             }, 'dependent_fields', 'Snake case within a list'),
+            ({
+                 "type": "structured",
+                 "allFields": [],
+                 "tensorFields": [],
+                 'annParameters': {
+                     'spaceType': 'dotproduct',
+                     'parameters': {
+                         'ef_construction': 128,
+                         'm': 16
+                     }
+                 }
+             }, 'ef_construction', 'Snake case within a dict'),
+            ({
+                 "type": "unstructured",
+                 'annParameters': {
+                     'spaceType': 'dotproduct',
+                     'parameters': {
+                         'ef_construction': 128,
+                         'm': 16
+                     }
+                 }
+             }, 'ef_construction', 'Snake case within a dict, unstructured index')
+        ]
+        for test_case, field, test_name in test_cases:
+            with self.subTest(test_name):
+                response = self.client.post(
+                    "/indexes/my_index",
+                    json=test_case
+                )
+
+                self.assertEqual(response.status_code, 422)
+                self.assertTrue(f"Invalid field name '{field}'" in response.text)