diff --git a/Makefile b/Makefile
index 7b93a43..7c8b8f0 100644
--- a/Makefile
+++ b/Makefile
@@ -1,15 +1,16 @@
-CC 	:= gcc
-AS	:= nasm
-ASFLAGS := -g -f elf64 -I src/
-CFLAGS  := -g -Wall -Wextra -Wno-override-init -std=c2x -fPIC -fPIE
-MAIN	:= $(wildcard *.c)
-SRC	:= $(wildcard src/*.s)
-OBJ_DIR := build
-OBJ_CC  := $(addprefix $(OBJ_DIR)/, $(patsubst %.c,%.o, $(MAIN)))
-OBJ_AS  := $(addprefix $(OBJ_DIR)/, $(patsubst %.s,%.o, $(SRC)))
-DIR 	:= .
-NAME    := main
-LIB_NAME:= asm
+CC		:= gcc
+AS		:= nasm
+ASFLAGS		:= -g -f elf64 -I src/
+CFLAGS		:= -g -Wall -Wextra -Wno-override-init -std=c2x -fPIC -fPIE
+MAIN		:= $(wildcard *.c)
+SRC		:= $(wildcard src/*.s)
+OBJ_DIR		:= build
+OBJ_CC		:= $(addprefix $(OBJ_DIR)/, $(patsubst %.c,%.o, $(MAIN)))
+OBJ_AS		:= $(addprefix $(OBJ_DIR)/, $(patsubst %.s,%.o, $(SRC)))
+DIR		:= .
+NAME		:= main
+LIB_NAME	:= asm
+PATH_LIB_NAME	:= $(OBJ_DIR)/lib$(LIB_NAME).a
 
 LD  	:= $(CC)
 LDFLAGS := -L$(OBJ_DIR) -l$(LIB_NAME) -fPIC -fPIE
@@ -17,10 +18,12 @@ LDFLAGS := -L$(OBJ_DIR) -l$(LIB_NAME) -fPIC -fPIE
 
 all: $(NAME)
 
-$(NAME): $(OBJ_CC) $(OBJ_AS)
-	ar rcs $(OBJ_DIR)/lib$(LIB_NAME).a $(OBJ_AS)
+$(NAME): $(PATH_LIB_NAME) $(OBJ_CC)
 	$(LD) $(OBJ_CC) $(LDFLAGS) -o $(DIR)/$(NAME)
 
+$(PATH_LIB_NAME): $(OBJ_AS)
+	ar rcs $(PATH_LIB_NAME) $(OBJ_AS)
+
 $(OBJ_DIR)/%.o: %.c
 	@mkdir -p $(@D)
 	$(CC) $(CFLAGS) -c -o $@ $<
@@ -30,9 +33,9 @@ $(OBJ_DIR)/%.o: %.s
 	$(AS) $(ASFLAGS) $< -o $@
 
 clean:
-	@rm -f $(NAME)
 	@rm -rf $(OBJ_DIR)
 
-re:
-	@make --no-print clean
-	@make --no-print all
+fclean: clean
+	@rm -f $(NAME)
+
+re: fclean all
diff --git a/main.c b/main.c
index 7624abe..74e5dda 100644
--- a/main.c
+++ b/main.c
@@ -185,6 +185,8 @@ test_calloc() {
 		char *empty = ft_calloc(0, 0);
 		printf("empty: %p\n", empty);
 
+		char *overflow = ft_calloc();
+
 		char *buf = ft_calloc(10, 1);
 		strcpy(buf, "test");
 		printf("test: %s_%p\n", buf, buf);
diff --git a/main.h b/main.h
index 0b43c56..474a49a 100644
--- a/main.h
+++ b/main.h
@@ -7,6 +7,7 @@
 #include <fcntl.h>
 #include <stdlib.h>
 #include <errno.h>
+#include <limit.h>
 
 // DONE
 extern size_t ft_strlen(const char *s);
diff --git a/src/ft_calloc.s b/src/ft_calloc.s
index e4dab1a..7fe6b09 100644
--- a/src/ft_calloc.s
+++ b/src/ft_calloc.s
@@ -9,7 +9,9 @@ section .text
 		push rbx
 		mov rbx, rdi
 
-		mov rdi, rbx
+		mul rbx, rsi
+		xor rdi, rdi
+		cmovno rdi, rbx; Move if not overflow
 		call malloc wrt ..plt 
 
 		cmp rax, 0