diff --git a/snowflake_utils/models.py b/snowflake_utils/models.py
index 3bbdb10..23e2417 100644
--- a/snowflake_utils/models.py
+++ b/snowflake_utils/models.py
@@ -4,7 +4,7 @@
 from enum import Enum
 from functools import partial
 
-from pydantic import BaseModel, Field
+from pydantic import BaseModel, Field, field_validator
 from snowflake.connector.cursor import SnowflakeCursor
 from typing_extensions import Self
 
@@ -65,6 +65,11 @@ def parsed_columns(self):
     def parse_from_json(self):
         raise NotImplementedError("Not implemented yet")
 
+    @field_validator("columns")
+    @classmethod
+    def force_columns_to_casefold(cls, value) -> dict:
+        return {k.casefold(): v for k, v in value.items()}
+
 
 class Schema(BaseModel):
     name: str
@@ -397,12 +402,15 @@ def sync_tags(self, cursor: SnowflakeCursor) -> None:
         desired_tags = {
             f"{column}.{tag_name}.{tag_value}".casefold(): (column, tag_name, tag_value)
             for column in self.table_structure.columns
-            for tag_name, tag_value in self.table_structure.columns[column].tags.items()
+            for tag_name, tag_value in self.table_structure.columns[
+                column.casefold()
+            ].tags.items()
         }
 
         for tag in existing_tags:
             if tag not in desired_tags:
-                self._unset_tag(cursor, *existing_tags[tag])
+                column, tag_name, _value = existing_tags[tag]
+                self._unset_tag(cursor, column, tag_name)
 
         for tag in desired_tags:
             if tag not in existing_tags: