diff --git a/README.md b/README.md
index 43b77a9..80cde26 100644
--- a/README.md
+++ b/README.md
@@ -95,6 +95,9 @@ Some [Faker providers](https://faker.readthedocs.io/en/master/providers/baseprov
 fake -n 10 "pyint(1;100),credit_card_number(amex),pystr_format(?#-####)" -f json -c id,credit_card_number,license_plate
 ```
 
+> [!IMPORTANT]
+> When using arguments with output formats like JSON, it's best to provide column headers as well with `-c`.
+
 And unique values are supported as well.
 
 ```bash
diff --git a/faker_cli/parser.py b/faker_cli/parser.py
index e3750d3..bc21573 100644
--- a/faker_cli/parser.py
+++ b/faker_cli/parser.py
@@ -1,6 +1,4 @@
-from typing import List, Tuple
-
-def infer_column_names(col_names, col_types: str) -> List[str]:
+def infer_column_names(col_names, col_types: str) -> list[str]:
     """
     Infer column names from column types
     """
@@ -11,7 +9,7 @@ def infer_column_names(col_names, col_types: str) -> List[str]:
     return col_types.split(",")
 
 
-def parse_column_types(input_string: str) -> List[Tuple[str, List]]:
+def parse_column_types(input_string: str) -> list[tuple[str, list]]:
     """
     Parse a string of the format "pyint(1;10),datetime,profile(ssn,birthdate)" and split it by commas with optional parenthese-inclosed arguments.
     """