diff --git a/Makefile b/Makefile
index 7b496e7..96cf167 100644
--- a/Makefile
+++ b/Makefile
@@ -12,7 +12,7 @@ _DEP	=	libft.h
 DEPS	=	$(_DEP:%.h=$(IDIR)/%.h)
 
 CFLAGS	=	-I$(IDIR)
-CFLAGS +=	-Wall -Wextra -Werror
+CFLAGS +=	-Wall -Wextra -Werror -g3
 
 SRCS	=	ft_memset.c \
 			ft_bzero.c \
diff --git a/srcs/ft_calloc.c b/srcs/ft_calloc.c
index 5c2ed9f..b84f0ee 100644
--- a/srcs/ft_calloc.c
+++ b/srcs/ft_calloc.c
@@ -11,13 +11,13 @@
 /* ************************************************************************** */
 
 /*
+**	allocate count * size byte of memory and
+**	return a pointer to the allocated memory
+**
 **	exemple allocation for 5 integers with malloc then calloc :
 **	a = (int *)malloc(5 * sizeof(int));	//5*4bytes = 20 bytes
 **	free(a);
 **	a = (int *)calloc(5, sizeof(int));
-**
-**	allocate count * size byte of memory and
-**	return a pointer to the allocated memory
 */
 
 /*
diff --git a/srcs/ft_get_next_line.c b/srcs/ft_get_next_line.c
index 65e545c..8b21774 100644
--- a/srcs/ft_get_next_line.c
+++ b/srcs/ft_get_next_line.c
@@ -123,7 +123,7 @@ int		get_next_line(const int fd, char **line)
 		if ((ret = read(fd, buf, BUFFER_SIZE)) < 0)
 			return (free_lst(&lst, -1));
 		buf[ret] = '\0';
-		if (!(lst->str = ft_strjoinfree(lst->str, buf)))
+		if (!(lst->str = ft_strjoinfree(lst->str, ft_strdup(buf))))
 			return (free_lst(&lst, -1));
 	}
 	if (str != NULL)
diff --git a/srcs/ft_lstadd_back.c b/srcs/ft_lstadd_back.c
index 37084d1..315119b 100644
--- a/srcs/ft_lstadd_back.c
+++ b/srcs/ft_lstadd_back.c
@@ -86,6 +86,5 @@ void	ft_lstadd_back(t_list **alst, t_list *new)
 				tmp = tmp->next;
 			tmp->next = new;
 		}
-		new->next = NULL;
 	}
 }
diff --git a/srcs/ft_lstdelone.c b/srcs/ft_lstdelone.c
index 3ff3259..0cf925a 100644
--- a/srcs/ft_lstdelone.c
+++ b/srcs/ft_lstdelone.c
@@ -90,7 +90,8 @@
 
 void	ft_lstdelone(t_list *lst, void (*del)(void *))
 {
-	del(lst->content);
+	if (lst->content && del)
+		del(lst->content);
 	free(lst);
 	lst = NULL;
 }
diff --git a/srcs/ft_strjoinfree.c b/srcs/ft_strjoinfree.c
index 394455d..66c8b50 100644
--- a/srcs/ft_strjoinfree.c
+++ b/srcs/ft_strjoinfree.c
@@ -12,7 +12,7 @@
 
 /*
 ** create a new string by concatenating the two strings s1 and s2
-** then free s1
+** then free s1 and s2
 */
 
 #include "libft.h"
@@ -24,5 +24,6 @@ char	*ft_strjoinfree(char *s1, char *s2)
 	if (!(str = ft_strjoin(s1, s2)))
 		return (NULL);
 	free(s1);
+	free(s2);
 	return (str);
 }