diff --git a/src/lib.rs b/src/lib.rs
index b967715..e6fe893 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -135,27 +135,27 @@ impl Ascii {
     }
 }
 
-impl fmt::String for Ascii {
+impl fmt::Display for Ascii {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        fmt::String::fmt(&(self.chr as char), f)
+        fmt::Display::fmt(&(self.chr as char), f)
     }
 }
 
-impl fmt::String for Vec<Ascii> {
+impl fmt::Display for Vec<Ascii> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        fmt::String::fmt(&self[], f)
+        fmt::Display::fmt(&self[], f)
     }
 }
 
-impl fmt::String for [Ascii] {
+impl fmt::Display for [Ascii] {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        fmt::String::fmt(self.as_str(), f)
+        fmt::Display::fmt(self.as_str(), f)
     }
 }
 
-impl fmt::Show for Ascii {
+impl fmt::Debug for Ascii {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        fmt::Show::fmt(&(self.chr as char), f)
+        fmt::Debug::fmt(&(self.chr as char), f)
     }
 }
 
@@ -344,30 +344,30 @@ mod tests {
 
     #[test]
     fn test_ascii() {
-        assert_eq!(65u8.to_ascii().unwrap().as_byte(), 65u8);
-        assert_eq!(65u8.to_ascii().unwrap().as_char(), 'A');
-        assert_eq!('A'.to_ascii().unwrap().as_char(), 'A');
-        assert_eq!('A'.to_ascii().unwrap().as_byte(), 65u8);
+        assert_eq!(65u8.to_ascii().ok().unwrap().as_byte(), 65u8);
+        assert_eq!(65u8.to_ascii().ok().unwrap().as_char(), 'A');
+        assert_eq!('A'.to_ascii().ok().unwrap().as_char(), 'A');
+        assert_eq!('A'.to_ascii().ok().unwrap().as_byte(), 65u8);
 
-        assert!('0'.to_ascii().unwrap().is_digit());
-        assert!('9'.to_ascii().unwrap().is_digit());
-        assert!(!'/'.to_ascii().unwrap().is_digit());
-        assert!(!':'.to_ascii().unwrap().is_digit());
+        assert!('0'.to_ascii().ok().unwrap().is_digit());
+        assert!('9'.to_ascii().ok().unwrap().is_digit());
+        assert!(!'/'.to_ascii().ok().unwrap().is_digit());
+        assert!(!':'.to_ascii().ok().unwrap().is_digit());
 
-        assert!(0x1f_u8.to_ascii().unwrap().is_control());
-        assert!(!' '.to_ascii().unwrap().is_control());
-        assert!(0x7f_u8.to_ascii().unwrap().is_control());
+        assert!(0x1f_u8.to_ascii().ok().unwrap().is_control());
+        assert!(!' '.to_ascii().ok().unwrap().is_control());
+        assert!(0x7f_u8.to_ascii().ok().unwrap().is_control());
     }
 
     #[test]
     fn test_ascii_vec() {
         let test = &[40u8, 32u8, 59u8];
         let b: &[_] = v2ascii!([40, 32, 59]);
-        assert_eq!(test.to_ascii().unwrap(), b);
-        assert_eq!("( ;".to_ascii().unwrap(), b);
+        assert_eq!(test.to_ascii().ok().unwrap(), b);
+        assert_eq!("( ;".to_ascii().ok().unwrap(), b);
         let v = vec![40u8, 32u8, 59u8];
-        assert_eq!(v.as_slice().to_ascii().unwrap(), b);
-        assert_eq!("( ;".to_string().as_slice().to_ascii().unwrap(), b);
+        assert_eq!(v.as_slice().to_ascii().ok().unwrap(), b);
+        assert_eq!("( ;".to_string().as_slice().to_ascii().ok().unwrap(), b);
     }
 
     #[test]
@@ -431,7 +431,7 @@ mod tests {
 
     #[test]
     fn fmt_string_ascii_slice() {
-        let s = "abc".to_ascii().unwrap();
+        let s = "abc".to_ascii().ok().unwrap();
         assert_eq!(format!("{}", s), "abc".to_string());
     }