diff --git a/sorting.c b/sorting.c
index 58a1b23..4bea4f5 100644
--- a/sorting.c
+++ b/sorting.c
@@ -38,7 +38,7 @@ int sort_natural(const void *file0, const void *file1){
 	long parsed_number0 = 0;
 	long parsed_number1 = 0;
 	char is_num = 0;
-	char result = 0;
+	signed char result = 0;
 
 	do {