diff --git a/main.py b/main.py
index fcc5b09..4e84b36 100644
--- a/main.py
+++ b/main.py
@@ -54,7 +54,7 @@ class DBConn:
         self.cur.execute(create_tbl_sql)
 
     def write_to_database(self, tbl, column_data):
-        col_names = column_data.keys()  # OrderedDict
+        col_names = list(column_data.keys())  # OrderedDict
 
         col_names_placeholder = ', '.join(
             [f"\"{x}\"" for x in col_names]
@@ -79,7 +79,7 @@ class DBConn:
                     self.cur.execute(f"alter table \"{tbl}\" add column \"{new_col}\" text")
 
                 print(f"added new cols {', '.join(not_found)} to {tbl}")
-                self.table_mapping[tbl] = col_names
+                self.table_mapping[tbl] = list(col_names)
 
         sql = f"insert into \"{tbl}\" ({col_names_placeholder}) values({value_placeholders})"
         if args.debug: