diff --git a/Makefile b/Makefile
index dc5bc39..0c19f7c 100644
--- a/Makefile
+++ b/Makefile
@@ -6,7 +6,7 @@
 #    By: lalgarra <lalgarra@student.42madrid.com>   +#+  +:+       +#+         #
 #                                                 +#+#+#+#+#+   +#+            #
 #    Created: 2025/10/03 18:03:12 by lalgarra          #+#    #+#              #
-#    Updated: 2025/10/03 21:16:37 by lalgarra         ###   ########.fr        #
+#    Updated: 2025/10/04 11:31:13 by lalgarra         ###   ########.fr        #
 #                                                                              #
 # **************************************************************************** #
 
@@ -17,7 +17,7 @@ LIBDIR = ../repo_libft_algarra
 CFLAGS += -Wall -Wextra -Werror -g3 -iquote $(LIBDIR) 
 
 TESTS := ft_isalpha_test ft_isdigit_test ft_isalnum_test ft_isascii_test \
-	ft_isprint_test
+	ft_isprint_test ft_toupper_test
 
 %_test : %_test.c
 	$(CC) $(CFLAGS) $*_test.c -L$(LIBDIR) -lft -o $*_test
diff --git a/ft_toupper_expected.output b/ft_toupper_expected.output
new file mode 100644
index 0000000..fd8a8a1
Binary files /dev/null and b/ft_toupper_expected.output differ
diff --git a/ft_toupper_test.c b/ft_toupper_test.c
new file mode 100644
index 0000000..beeaac5
--- /dev/null
+++ b/ft_toupper_test.c
@@ -0,0 +1,42 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   ft_toupper_test.c                                  :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: lalgarra <lalgarra@student.42madrid.com>   +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2025/10/03 18:27:44 by lalgarra          #+#    #+#             */
+/*   Updated: 2025/10/04 11:38:26 by lalgarra         ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#include "libft.h"
+#include <stdio.h>
+#include <limits.h>
+
+int	main(void)
+{
+	int	p1;
+
+	p1 = 0;
+	while (p1 < 256)
+	{
+		printf("'%c' (%i); ft_toupper(c): %i\r\n", p1, p1, ft_toupper(p1));
+		p1++;
+	}
+	p1 = -1;
+	printf("'%c' (%i); ft_toupper(c): %i\r\n", p1, p1, ft_toupper(p1));
+	p1 = INT_MIN;
+	while (p1 < INT_MIN + 3)
+	{
+		printf("'%c' (%i); ft_toupper(c): %i\r\n", p1, p1, ft_toupper(p1));
+		p1++;
+	}
+	p1 = INT_MAX;
+	while (p1 < INT_MAX - 3)
+	{
+		printf("'%c' (%i); ft_toupper(c): %i\r\n", p1, p1, ft_toupper(p1));
+		p1--;
+	}
+	return (0);
+}