diff --git a/src/libcore/tests/ascii.rs b/src/libcore/tests/ascii.rs
index 4d43067ad2cf3..950222dbcfa3f 100644
--- a/src/libcore/tests/ascii.rs
+++ b/src/libcore/tests/ascii.rs
@@ -9,7 +9,6 @@
 // except according to those terms.
 
 use core::char::from_u32;
-use std::ascii::AsciiExt;
 
 #[test]
 fn test_is_ascii() {
@@ -143,8 +142,6 @@ macro_rules! assert_all {
                            stringify!($what), b);
                 }
             }
-            assert!($str.$what());
-            assert!($str.as_bytes().$what());
         )+
     }};
     ($what:ident, $($str:tt),+,) => (assert_all!($what,$($str),+))
diff --git a/src/libstd/ascii.rs b/src/libstd/ascii.rs
index 0837ff91c142d..6472edb0aa7d3 100644
--- a/src/libstd/ascii.rs
+++ b/src/libstd/ascii.rs
@@ -52,6 +52,7 @@ pub use core::ascii::{EscapeDefault, escape_default};
 ///
 /// [combining character]: https://en.wikipedia.org/wiki/Combining_character
 #[stable(feature = "rust1", since = "1.0.0")]
+#[rustc_deprecated(since = "1.26.0", reason = "use inherent methods instead")]
 pub trait AsciiExt {
     /// Container type for copied ASCII characters.
     #[stable(feature = "rust1", since = "1.0.0")]
@@ -84,6 +85,7 @@ pub trait AsciiExt {
     /// [`make_ascii_uppercase`]: #tymethod.make_ascii_uppercase
     /// [`str::to_uppercase`]: ../primitive.str.html#method.to_uppercase
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[allow(deprecated)]
     fn to_ascii_uppercase(&self) -> Self::Owned;
 
     /// Makes a copy of the value in its ASCII lower case equivalent.
@@ -104,6 +106,7 @@ pub trait AsciiExt {
     /// [`make_ascii_lowercase`]: #tymethod.make_ascii_lowercase
     /// [`str::to_lowercase`]: ../primitive.str.html#method.to_lowercase
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[allow(deprecated)]
     fn to_ascii_lowercase(&self) -> Self::Owned;
 
     /// Checks that two values are an ASCII case-insensitive match.
@@ -162,6 +165,7 @@ pub trait AsciiExt {
     /// This method will be deprecated in favor of the identically-named
     /// inherent methods on `u8`, `char`, `[u8]` and `str`.
     #[unstable(feature = "ascii_ctype", issue = "39658")]
+    #[rustc_deprecated(since = "1.26.0", reason = "use inherent methods instead")]
     fn is_ascii_alphabetic(&self) -> bool { unimplemented!(); }
 
     /// Checks if the value is an ASCII uppercase character:
@@ -174,6 +178,7 @@ pub trait AsciiExt {
     /// This method will be deprecated in favor of the identically-named
     /// inherent methods on `u8`, `char`, `[u8]` and `str`.
     #[unstable(feature = "ascii_ctype", issue = "39658")]
+    #[rustc_deprecated(since = "1.26.0", reason = "use inherent methods instead")]
     fn is_ascii_uppercase(&self) -> bool { unimplemented!(); }
 
     /// Checks if the value is an ASCII lowercase character:
@@ -186,6 +191,7 @@ pub trait AsciiExt {
     /// This method will be deprecated in favor of the identically-named
     /// inherent methods on `u8`, `char`, `[u8]` and `str`.
     #[unstable(feature = "ascii_ctype", issue = "39658")]
+    #[rustc_deprecated(since = "1.26.0", reason = "use inherent methods instead")]
     fn is_ascii_lowercase(&self) -> bool { unimplemented!(); }
 
     /// Checks if the value is an ASCII alphanumeric character:
@@ -199,6 +205,7 @@ pub trait AsciiExt {
     /// This method will be deprecated in favor of the identically-named
     /// inherent methods on `u8`, `char`, `[u8]` and `str`.
     #[unstable(feature = "ascii_ctype", issue = "39658")]
+    #[rustc_deprecated(since = "1.26.0", reason = "use inherent methods instead")]
     fn is_ascii_alphanumeric(&self) -> bool { unimplemented!(); }
 
     /// Checks if the value is an ASCII decimal digit:
@@ -211,6 +218,7 @@ pub trait AsciiExt {
     /// This method will be deprecated in favor of the identically-named
     /// inherent methods on `u8`, `char`, `[u8]` and `str`.
     #[unstable(feature = "ascii_ctype", issue = "39658")]
+    #[rustc_deprecated(since = "1.26.0", reason = "use inherent methods instead")]
     fn is_ascii_digit(&self) -> bool { unimplemented!(); }
 
     /// Checks if the value is an ASCII hexadecimal digit:
@@ -224,6 +232,7 @@ pub trait AsciiExt {
     /// This method will be deprecated in favor of the identically-named
     /// inherent methods on `u8`, `char`, `[u8]` and `str`.
     #[unstable(feature = "ascii_ctype", issue = "39658")]
+    #[rustc_deprecated(since = "1.26.0", reason = "use inherent methods instead")]
     fn is_ascii_hexdigit(&self) -> bool { unimplemented!(); }
 
     /// Checks if the value is an ASCII punctuation character:
@@ -241,6 +250,7 @@ pub trait AsciiExt {
     /// This method will be deprecated in favor of the identically-named
     /// inherent methods on `u8`, `char`, `[u8]` and `str`.
     #[unstable(feature = "ascii_ctype", issue = "39658")]
+    #[rustc_deprecated(since = "1.26.0", reason = "use inherent methods instead")]
     fn is_ascii_punctuation(&self) -> bool { unimplemented!(); }
 
     /// Checks if the value is an ASCII graphic character:
@@ -253,6 +263,7 @@ pub trait AsciiExt {
     /// This method will be deprecated in favor of the identically-named
     /// inherent methods on `u8`, `char`, `[u8]` and `str`.
     #[unstable(feature = "ascii_ctype", issue = "39658")]
+    #[rustc_deprecated(since = "1.26.0", reason = "use inherent methods instead")]
     fn is_ascii_graphic(&self) -> bool { unimplemented!(); }
 
     /// Checks if the value is an ASCII whitespace character:
@@ -282,6 +293,7 @@ pub trait AsciiExt {
     /// This method will be deprecated in favor of the identically-named
     /// inherent methods on `u8`, `char`, `[u8]` and `str`.
     #[unstable(feature = "ascii_ctype", issue = "39658")]
+    #[rustc_deprecated(since = "1.26.0", reason = "use inherent methods instead")]
     fn is_ascii_whitespace(&self) -> bool { unimplemented!(); }
 
     /// Checks if the value is an ASCII control character:
@@ -294,6 +306,7 @@ pub trait AsciiExt {
     /// This method will be deprecated in favor of the identically-named
     /// inherent methods on `u8`, `char`, `[u8]` and `str`.
     #[unstable(feature = "ascii_ctype", issue = "39658")]
+    #[rustc_deprecated(since = "1.26.0", reason = "use inherent methods instead")]
     fn is_ascii_control(&self) -> bool { unimplemented!(); }
 }
 
@@ -354,6 +367,7 @@ macro_rules! delegating_ascii_ctype_methods {
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
+#[allow(deprecated)]
 impl AsciiExt for u8 {
     type Owned = u8;
 
@@ -362,6 +376,7 @@ impl AsciiExt for u8 {
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
+#[allow(deprecated)]
 impl AsciiExt for char {
     type Owned = char;
 
@@ -370,6 +385,7 @@ impl AsciiExt for char {
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
+#[allow(deprecated)]
 impl AsciiExt for [u8] {
     type Owned = Vec<u8>;
 
@@ -427,6 +443,7 @@ impl AsciiExt for [u8] {
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
+#[allow(deprecated)]
 impl AsciiExt for str {
     type Owned = String;
 
diff --git a/src/libstd/sys/windows/process.rs b/src/libstd/sys/windows/process.rs
index f1ab9c4760965..afa8e3e136935 100644
--- a/src/libstd/sys/windows/process.rs
+++ b/src/libstd/sys/windows/process.rs
@@ -10,7 +10,6 @@
 
 #![unstable(feature = "process_internals", issue = "0")]
 
-use ascii::AsciiExt;
 use collections::BTreeMap;
 use env::split_paths;
 use env;
diff --git a/src/libstd/sys_common/wtf8.rs b/src/libstd/sys_common/wtf8.rs
index 9fff8b91f96f3..78b2bb5fe6e2f 100644
--- a/src/libstd/sys_common/wtf8.rs
+++ b/src/libstd/sys_common/wtf8.rs
@@ -27,7 +27,6 @@
 
 use core::str::next_code_point;
 
-use ascii::*;
 use borrow::Cow;
 use char;
 use fmt;
@@ -871,24 +870,22 @@ impl Hash for Wtf8 {
     }
 }
 
-impl AsciiExt for Wtf8 {
-    type Owned = Wtf8Buf;
-
-    fn is_ascii(&self) -> bool {
+impl Wtf8 {
+    pub fn is_ascii(&self) -> bool {
         self.bytes.is_ascii()
     }
-    fn to_ascii_uppercase(&self) -> Wtf8Buf {
+    pub fn to_ascii_uppercase(&self) -> Wtf8Buf {
         Wtf8Buf { bytes: self.bytes.to_ascii_uppercase() }
     }
-    fn to_ascii_lowercase(&self) -> Wtf8Buf {
+    pub fn to_ascii_lowercase(&self) -> Wtf8Buf {
         Wtf8Buf { bytes: self.bytes.to_ascii_lowercase() }
     }
-    fn eq_ignore_ascii_case(&self, other: &Wtf8) -> bool {
+    pub fn eq_ignore_ascii_case(&self, other: &Wtf8) -> bool {
         self.bytes.eq_ignore_ascii_case(&other.bytes)
     }
 
-    fn make_ascii_uppercase(&mut self) { self.bytes.make_ascii_uppercase() }
-    fn make_ascii_lowercase(&mut self) { self.bytes.make_ascii_lowercase() }
+    pub fn make_ascii_uppercase(&mut self) { self.bytes.make_ascii_uppercase() }
+    pub fn make_ascii_lowercase(&mut self) { self.bytes.make_ascii_lowercase() }
 }
 
 #[cfg(test)]
diff --git a/src/test/run-pass/issue-10683.rs b/src/test/run-pass/issue-10683.rs
index eb2177202a22b..d3ba477fa573e 100644
--- a/src/test/run-pass/issue-10683.rs
+++ b/src/test/run-pass/issue-10683.rs
@@ -10,8 +10,6 @@
 
 // pretty-expanded FIXME #23616
 
-use std::ascii::AsciiExt;
-
 static NAME: &'static str = "hello world";
 
 fn main() {