diff --git a/include/level.h b/include/level.h
index 835cf16..c5abc00 100644
--- a/include/level.h
+++ b/include/level.h
@@ -3,10 +3,11 @@
 
 #pragma once
 
+typedef unsigned int tile_t;
 struct Level {
 	int width;
 	int height;
-	int *data;
+	tile_t *data;
 };
 
 void level_read(struct Level*, char *path);
diff --git a/src/level.c b/src/level.c
index d040571..5a42756 100644
--- a/src/level.c
+++ b/src/level.c
@@ -1,7 +1,6 @@
 /* SPDX-License-Identifier: GPL-3.0-or-later */
 /* Copyright (C) 2021 KikooDX */
 
-#include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -10,18 +9,18 @@
 
 static const int kble_fmt_version = 0;
 
-static int read_byte(FILE *file);
-static int read_byte_group(FILE *file, int size);
-static void write_byte(FILE *file, unsigned char byte);
-static void write_byte_group(FILE *file, int value, int size);
+static char read_byte(FILE *file);
+static tile_t read_byte_group(FILE *file, int size);
+static void write_byte(FILE *file, char byte);
+static void write_byte_group(FILE *file, tile_t value, int size);
 
 void level_read(struct Level *level, char *path) {
 	FILE *file = NULL;
-	int byte = 0;
-	int tile_size = 0;
+	char byte = 0;
+	unsigned int tile_size = 0;
 	int level_size = 0;
-	int tile = 0;
 	int i = 0;
+	tile_t tile = 0;
 
 	/* open file in read mode */
 	file = fopen(path, "rb");
@@ -40,6 +39,12 @@ void level_read(struct Level *level, char *path) {
 
 	/* get tile size (in bytes) */
 	tile_size = read_byte(file);
+	/* check than tile size is in boundaries */
+	if (tile_size > sizeof(tile_t) / sizeof(char)) {
+    		fprintf(stderr, "ERROR: tile size is too big ; "
+    			"maximum is %ld, found %d", sizeof(tile_t), tile_size);
+    		exit(EXIT_FAILURE);
+	}
 	/* get width */
 	level->width = read_byte_group(file, 2);
 	/* get height */
@@ -48,9 +53,9 @@ void level_read(struct Level *level, char *path) {
 	/* allocate memory for data */
 	level_size = level->width * level->height;
 	if (level->data == NULL) {
-		level->data = malloc(level_size * sizeof(int));
+		level->data = malloc(level_size * sizeof(tile_t));
 	} else {
-		level->data = realloc(level->data, level_size * sizeof(int));
+		level->data = realloc(level->data, level_size * sizeof(tile_t));
 	}
 	/* check for allocation failure */
 	if (level->data == NULL) {
@@ -116,32 +121,30 @@ void level_write(struct Level level, char *path) {
 }
 
 /* Read a single byte safely (handle EOF). */
-static int read_byte(FILE *file) {
+static char read_byte(FILE *file) {
 	const int byte = fgetc(file);
 	if (byte == EOF) {
 		fprintf(stderr, "ERROR: unexpected EOF\n");
 		exit(EXIT_FAILURE);
 	}
-	return byte;
+	return (char)byte;
 }
 
 /* Read multiple bytes and "merge" them into one integer. */
-static int read_byte_group(FILE *file, int size) {
+static tile_t read_byte_group(FILE *file, int size) {
 	int group = 0;
-	uint8_t *byte_ptr = (uint8_t*)&group;
+	char *byte_ptr = (char*)&group;
 	int i = 0;
 	byte_ptr += size;
 	for (i = 0; i < size; i += 1) {
-		byte_ptr -= 1;
+		byte_ptr -= 1,
 		*byte_ptr = read_byte(file);
-		printf("%d ", *byte_ptr);
 	}
-	printf("%d\n", group);
 	return group;
 }
 
 /* Write a single byte safely (handle EOF). */
-static void write_byte(FILE *file, unsigned char byte) {
+static void write_byte(FILE *file, char byte) {
 	const int result = fputc(byte, file);
 	if (result == EOF) {
 		fprintf(stderr, "ERROR: file write error\n");
@@ -150,14 +153,12 @@ static void write_byte(FILE *file, unsigned char byte) {
 }
 
 /* Write an integer as multiple bytes. */
-static void write_byte_group(FILE *file, int value, int size) {
-	uint8_t *value_ptr = (uint8_t*)&value;
+static void write_byte_group(FILE *file, tile_t value, int size) {
+	char *value_ptr = (char*)&value;
 	value_ptr += size;
 	int i = 0;
 	for (i = 0; i < size; i += 1) {
 		value_ptr -= 1;
-    		printf("%d ", *value_ptr);
 		write_byte(file, *value_ptr);
 	}
-	printf("\n");
 }