diff --git a/Makefile b/Makefile
index e003bc0..5b52b42 100644
--- a/Makefile
+++ b/Makefile
@@ -127,7 +127,7 @@ SRCS	=	ft_memset.c \
 			ft_greater.c \
 			ft_smaller.c \
 			ft_sign.c \
-			ft_sign_f.c \
+			ft_fsign.c \
 			ft_modf.c \
 			ft_pow.c \
 			ft_sqrt.c \
diff --git a/includes/libft.h b/includes/libft.h
index 93c4990..99aca00 100644
--- a/includes/libft.h
+++ b/includes/libft.h
@@ -129,7 +129,7 @@ double ft_fabs(double n);
 int ft_greater(int a, int b);
 int ft_smaller(int a, int b);
 int ft_sign(int i);
-int ft_sign_f(double i);
+int ft_fsign(double i);
 double ft_modf(double x, double *int_part);
 double ft_pow(double base, int exponent);
 double ft_round(double x);
diff --git a/srcs/ft_sign_f.c b/srcs/ft_fsign.c
similarity index 53%
rename from srcs/ft_sign_f.c
rename to srcs/ft_fsign.c
index 141fbf0..b45fa01 100644
--- a/srcs/ft_sign_f.c
+++ b/srcs/ft_fsign.c
@@ -1,8 +1,10 @@
 #include "libft.h"
 
-int ft_sign_f(double i)
+int ft_fsign(double i)
 {
 	if (i < 0)
 		return (-1);
+	else if (i == 0)
+		return (0);
 	return (1);
 }