diff --git a/serde/src/de/mod.rs b/serde/src/de/mod.rs
index 9e81806e..7acd8b98 100644
--- a/serde/src/de/mod.rs
+++ b/serde/src/de/mod.rs
@@ -123,7 +123,6 @@ mod format;
 mod ignored_any;
 mod impls;
 pub(crate) mod size_hint;
-mod utf8;
 
 pub use self::ignored_any::IgnoredAny;
 
@@ -1478,7 +1477,7 @@ pub trait Visitor<'de>: Sized {
     where
         E: Error,
     {
-        self.visit_str(utf8::encode(v).as_str())
+        self.visit_str(v.encode_utf8(&mut [0u8; 4]))
     }
 
     /// The input contains a string. The lifetime of the string is ephemeral and
diff --git a/serde/src/de/utf8.rs b/serde/src/de/utf8.rs
deleted file mode 100644
index 16bd67e8..00000000
--- a/serde/src/de/utf8.rs
+++ /dev/null
@@ -1,46 +0,0 @@
-use crate::lib::*;
-
-const TAG_CONT: u8 = 0b1000_0000;
-const TAG_TWO_B: u8 = 0b1100_0000;
-const TAG_THREE_B: u8 = 0b1110_0000;
-const TAG_FOUR_B: u8 = 0b1111_0000;
-const MAX_ONE_B: u32 = 0x80;
-const MAX_TWO_B: u32 = 0x800;
-const MAX_THREE_B: u32 = 0x10000;
-
-#[inline]
-pub fn encode(c: char) -> Encode {
-    let code = c as u32;
-    let mut buf = [0; 4];
-    let pos = if code < MAX_ONE_B {
-        buf[3] = code as u8;
-        3
-    } else if code < MAX_TWO_B {
-        buf[2] = (code >> 6 & 0x1F) as u8 | TAG_TWO_B;
-        buf[3] = (code & 0x3F) as u8 | TAG_CONT;
-        2
-    } else if code < MAX_THREE_B {
-        buf[1] = (code >> 12 & 0x0F) as u8 | TAG_THREE_B;
-        buf[2] = (code >> 6 & 0x3F) as u8 | TAG_CONT;
-        buf[3] = (code & 0x3F) as u8 | TAG_CONT;
-        1
-    } else {
-        buf[0] = (code >> 18 & 0x07) as u8 | TAG_FOUR_B;
-        buf[1] = (code >> 12 & 0x3F) as u8 | TAG_CONT;
-        buf[2] = (code >> 6 & 0x3F) as u8 | TAG_CONT;
-        buf[3] = (code & 0x3F) as u8 | TAG_CONT;
-        0
-    };
-    Encode { buf, pos }
-}
-
-pub struct Encode {
-    buf: [u8; 4],
-    pos: usize,
-}
-
-impl Encode {
-    pub fn as_str(&self) -> &str {
-        str::from_utf8(&self.buf[self.pos..]).unwrap()
-    }
-}