diff --git a/src/libcollections/fmt.rs b/src/libcollections/fmt.rs
index 3dc193fdc62..bfa8f1b4190 100644
--- a/src/libcollections/fmt.rs
+++ b/src/libcollections/fmt.rs
@@ -262,7 +262,6 @@
 //! Example usage is:
 //!
 //! ```
-//! # #![feature(old_io)]
 //! # #![allow(unused_must_use)]
 //! use std::io::Write;
 //! let mut w = Vec::new();
@@ -290,7 +289,6 @@
 //! off, some example usage is:
 //!
 //! ```
-//! # #![feature(old_io)]
 //! use std::fmt;
 //! use std::io::{self, Write};
 //!
diff --git a/src/libserialize/json.rs b/src/libserialize/json.rs
index 4255899aa01..d042ef79233 100644
--- a/src/libserialize/json.rs
+++ b/src/libserialize/json.rs
@@ -2059,7 +2059,7 @@ impl<T: Iterator<Item=char>> Builder<T> {
     }
 }
 
-/// Decodes a json value from an `&mut old_io::Reader`
+/// Decodes a json value from an `&mut io::Read`
 pub fn from_reader(rdr: &mut Read) -> Result<Json, BuilderError> {
     let mut contents = Vec::new();
     match rdr.read_to_end(&mut contents) {
diff --git a/src/libstd/panicking.rs b/src/libstd/panicking.rs
index a498e634185..11b057d0094 100644
--- a/src/libstd/panicking.rs
+++ b/src/libstd/panicking.rs
@@ -19,7 +19,6 @@ use rt::{backtrace, unwind};
 use sys::stdio::Stderr;
 use thread;
 
-// Defined in this module instead of old_io::stdio so that the unwinding
 thread_local! {
     pub static LOCAL_STDERR: RefCell<Option<Box<Write + Send>>> = {
         RefCell::new(None)
diff --git a/src/libtest/lib.rs b/src/libtest/lib.rs
index 5c967747104..4f350b909ca 100644
--- a/src/libtest/lib.rs
+++ b/src/libtest/lib.rs
@@ -43,7 +43,6 @@
 #![feature(std_misc)]
 #![feature(libc)]
 #![feature(set_stdio)]
-#![cfg_attr(test, feature(old_io))]
 
 extern crate getopts;
 extern crate serialize;
diff --git a/src/test/auxiliary/linkage-visibility.rs b/src/test/auxiliary/linkage-visibility.rs
index d96dfd848f3..6cc2d427c25 100644
--- a/src/test/auxiliary/linkage-visibility.rs
+++ b/src/test/auxiliary/linkage-visibility.rs
@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(std_misc, old_path)]
+#![feature(std_misc)]
 
 use std::dynamic_lib::DynamicLibrary;
 
diff --git a/src/test/debuginfo/issue13213.rs b/src/test/debuginfo/issue13213.rs
index 13dc0c6d120..67975d02b19 100644
--- a/src/test/debuginfo/issue13213.rs
+++ b/src/test/debuginfo/issue13213.rs
@@ -12,8 +12,6 @@
 
 // aux-build:issue13213aux.rs
 
-#![feature(old_io)]
-
 extern crate issue13213aux;
 
 // compile-flags:-g
diff --git a/src/test/run-make/cannot-read-embedded-idents/create_and_compile.rs b/src/test/run-make/cannot-read-embedded-idents/create_and_compile.rs
index 02af5244b8a..fd69d2786b8 100644
--- a/src/test/run-make/cannot-read-embedded-idents/create_and_compile.rs
+++ b/src/test/run-make/cannot-read-embedded-idents/create_and_compile.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(old_io, old_path)]
-
 use std::env;
 use std::fs::File;
 use std::process::Command;
diff --git a/src/test/run-make/extern-fn-reachable/main.rs b/src/test/run-make/extern-fn-reachable/main.rs
index b93bdbaa16f..244f32b8ee5 100644
--- a/src/test/run-make/extern-fn-reachable/main.rs
+++ b/src/test/run-make/extern-fn-reachable/main.rs
@@ -8,10 +8,9 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(std_misc, old_path, os)]
+#![feature(std_misc)]
 
 use std::dynamic_lib::DynamicLibrary;
-use std::os;
 use std::path::Path;
 
 pub fn main() {
diff --git a/src/test/run-pass/closure-reform.rs b/src/test/run-pass/closure-reform.rs
index 50f05c050b1..0fa67e873f8 100644
--- a/src/test/run-pass/closure-reform.rs
+++ b/src/test/run-pass/closure-reform.rs
@@ -11,9 +11,7 @@
 /* Any copyright is dedicated to the Public Domain.
  * http://creativecommons.org/publicdomain/zero/1.0/ */
 
-#![feature(unboxed_closures, old_io)]
-
-use std::mem;
+#![feature(unboxed_closures)]
 
 fn call_it<F>(f: F)
     where F : FnOnce(String) -> String
diff --git a/src/test/run-pass/issue-10626.rs b/src/test/run-pass/issue-10626.rs
index 0d8f2225485..c81e16ebb7c 100644
--- a/src/test/run-pass/issue-10626.rs
+++ b/src/test/run-pass/issue-10626.rs
@@ -12,8 +12,6 @@
 // Make sure that if a process doesn't have its stdio/stderr descriptors set up
 // that we don't die in a large ball of fire
 
-#![feature(old_io)]
-
 use std::env;
 use std::process::{Command, Stdio};
 
diff --git a/src/test/run-pass/issue-11881.rs b/src/test/run-pass/issue-11881.rs
index 483ae02d2dc..9da04f72355 100644
--- a/src/test/run-pass/issue-11881.rs
+++ b/src/test/run-pass/issue-11881.rs
@@ -9,7 +9,7 @@
 // except according to those terms.
 
 
-#![feature(rustc_private, old_io)]
+#![feature(rustc_private)]
 
 extern crate rbml;
 extern crate serialize;
diff --git a/src/test/run-pass/issue-14940.rs b/src/test/run-pass/issue-14940.rs
index b51afc1d020..ba6815d5b7c 100644
--- a/src/test/run-pass/issue-14940.rs
+++ b/src/test/run-pass/issue-14940.rs
@@ -9,8 +9,6 @@
 // except according to those terms.
 
 
-#![feature(old_io, io)]
-
 use std::env;
 use std::process::Command;
 use std::io::{self, Write};
diff --git a/src/test/run-pass/linkage-visibility.rs b/src/test/run-pass/linkage-visibility.rs
index 945cf9370f4..74da4273b6a 100644
--- a/src/test/run-pass/linkage-visibility.rs
+++ b/src/test/run-pass/linkage-visibility.rs
@@ -12,7 +12,7 @@
 // ignore-android: FIXME(#10379)
 // ignore-windows: std::dynamic_lib does not work on Windows well
 
-#![feature(std_misc, old_path)]
+#![feature(std_misc)]
 
 extern crate linkage_visibility as foo;
 
diff --git a/src/test/run-pass/logging-separate-lines.rs b/src/test/run-pass/logging-separate-lines.rs
index 29cfe91eba5..09759326afd 100644
--- a/src/test/run-pass/logging-separate-lines.rs
+++ b/src/test/run-pass/logging-separate-lines.rs
@@ -12,7 +12,7 @@
 // exec-env:RUST_LOG=debug
 // compile-flags:-C debug-assertions=y
 
-#![feature(old_io, rustc_private)]
+#![feature(rustc_private)]
 
 #[macro_use]
 extern crate log;
diff --git a/src/test/run-pass/method-mut-self-modifies-mut-slice-lvalue.rs b/src/test/run-pass/method-mut-self-modifies-mut-slice-lvalue.rs
index 1611a2c0722..5eecf27db67 100644
--- a/src/test/run-pass/method-mut-self-modifies-mut-slice-lvalue.rs
+++ b/src/test/run-pass/method-mut-self-modifies-mut-slice-lvalue.rs
@@ -13,9 +13,8 @@
 // temporary. Issue #19147.
 
 
-#![feature(core, old_io)]
+#![feature(core)]
 
-use std::mem;
 use std::slice;
 
 pub type IoResult<T> = Result<T, ()>;
diff --git a/src/test/run-pass/process-spawn-with-unicode-params.rs b/src/test/run-pass/process-spawn-with-unicode-params.rs
index 32448d100fb..a155ee396b6 100644
--- a/src/test/run-pass/process-spawn-with-unicode-params.rs
+++ b/src/test/run-pass/process-spawn-with-unicode-params.rs
@@ -17,15 +17,13 @@
 // intact.
 
 // ignore-aarch64
-#![feature(path, fs, os, io, old_path)]
 
 use std::io::prelude::*;
 use std::io;
 use std::fs;
 use std::process::Command;
-use std::os;
 use std::env;
-use std::path::{Path, PathBuf};
+use std::path::Path;
 
 fn main() {
     let my_args = env::args().collect::<Vec<_>>();
diff --git a/src/test/run-pass/running-with-no-runtime.rs b/src/test/run-pass/running-with-no-runtime.rs
index 31d97305e0b..db543116d17 100644
--- a/src/test/run-pass/running-with-no-runtime.rs
+++ b/src/test/run-pass/running-with-no-runtime.rs
@@ -8,16 +8,12 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(start, os, std_misc, old_io)]
+#![feature(start, std_misc)]
 
 use std::ffi::CStr;
 use std::process::{Command, Output};
-use std::os;
 use std::rt::unwind::try;
-use std::rt;
 use std::str;
-use std::thread::Thread;
-use std::thunk::Thunk;
 
 #[start]
 fn start(argc: isize, argv: *const *const u8) -> isize {
diff --git a/src/test/run-pass/task-stderr.rs b/src/test/run-pass/task-stderr.rs
index 7bcde7b83cd..542756d1c4a 100644
--- a/src/test/run-pass/task-stderr.rs
+++ b/src/test/run-pass/task-stderr.rs
@@ -10,8 +10,7 @@
 
 // pretty-expanded FIXME #23616
 
-#![allow(unknown_features)]
-#![feature(box_syntax, old_io, std_misc, io, set_panic, set_stdio)]
+#![feature(box_syntax, set_stdio)]
 
 use std::io::prelude::*;
 use std::io;
diff --git a/src/test/run-pass/trait-coercion.rs b/src/test/run-pass/trait-coercion.rs
index fa31d9891aa..d40d9c89f89 100644
--- a/src/test/run-pass/trait-coercion.rs
+++ b/src/test/run-pass/trait-coercion.rs
@@ -8,8 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![allow(unknown_features)]
-#![feature(box_syntax, old_io, io)]
+#![feature(box_syntax)]
 
 use std::io::{self, Write};