diff --git a/src/header/assert/mod.rs b/src/header/assert/mod.rs
index 838050f9ac752c4399d24213372f5aa8ba196b76..ffbcecffda964e2ed72c1503745159c02f62b296 100644
--- a/src/header/assert/mod.rs
+++ b/src/header/assert/mod.rs
@@ -3,7 +3,6 @@
 use c_str::CStr;
 use core::fmt::Write;
 use header::{stdio, stdlib};
-use platform;
 use platform::types::*;
 
 #[no_mangle]
diff --git a/src/header/netdb/linux.rs b/src/header/netdb/linux.rs
index 400c07a6c7d70dea136c09b85abcdc25f1d05d8d..5eb07b3336a2a9edf90923e73bc439b75bb2b6fa 100644
--- a/src/header/netdb/linux.rs
+++ b/src/header/netdb/linux.rs
@@ -12,7 +12,7 @@ pub fn get_dns_server() -> String {
         Ok(file) => file,
         Err(_) => return String::new(), // TODO: better error handling
     };
-    let mut file = BufReader::new(file);
+    let file = BufReader::new(file);
 
     for line in file.split(b'\n') {
         let mut line = match line {
diff --git a/src/header/netdb/mod.rs b/src/header/netdb/mod.rs
index 0f81980ca9316fa4f12e9d81f14fadfc8639a970..485b83383d699a4811f3ef9d42a22be256728c1d 100644
--- a/src/header/netdb/mod.rs
+++ b/src/header/netdb/mod.rs
@@ -227,15 +227,11 @@ fn lookup_host(host: &str) -> Result<LookupHost, c_int> {
             Box::from_raw(packet_data_ptr);
         }
 
-        let mut i = 0 as socklen_t;
+        let i = 0 as socklen_t;
         let mut buf = [0u8; 65536];
         let buf_ptr = buf.as_mut_ptr() as *mut c_void;
 
-        let mut count = -1;
-
-        unsafe {
-            count = sys_socket::recv(sock, buf_ptr, 65536, 0);
-        }
+        let count = unsafe { sys_socket::recv(sock, buf_ptr, 65536, 0) };
         if count < 0 {
             return Err(EIO);
         }
@@ -347,15 +343,11 @@ fn lookup_addr(addr: in_addr) -> Result<Vec<Vec<u8>>, c_int> {
             Box::from_raw(packet_data_ptr);
         }
 
-        let mut i = mem::size_of::<sockaddr_in>() as socklen_t;
+        let i = mem::size_of::<sockaddr_in>() as socklen_t;
         let mut buf = [0u8; 65536];
         let buf_ptr = buf.as_mut_ptr() as *mut c_void;
 
-        let mut count = -1;
-
-        unsafe {
-            count = sys_socket::recv(sock, buf_ptr, 65536, 0);
-        }
+        let count = unsafe { sys_socket::recv(sock, buf_ptr, 65536, 0) };
         if count < 0 {
             return Err(EIO);
         }
@@ -385,11 +377,10 @@ fn lookup_addr(addr: in_addr) -> Result<Vec<Vec<u8>>, c_int> {
 
 fn parse_revdns_answer(data: Vec<u8>) -> Vec<u8> {
     let mut cursor = 0;
-    let mut offset = 0;
     let mut index = 0;
     let mut output = data.clone();
     while index < data.len() - 1 {
-        offset = data[index] as usize;
+        let offset = data[index] as usize;
         index = cursor + offset + 1;
         output[index] = '.' as u8;
         cursor = index;
@@ -855,10 +846,10 @@ pub unsafe extern "C" fn getservent() -> *const servent {
     let mut rlb = RawLineBuffer::new(SERVDB);
     rlb.seek(S_POS);
 
-    let mut r: Box<str> = Box::default();
+    let r: Box<str> = Box::default();
 
     loop {
-        let mut r = match rlb.next() {
+        let r = match rlb.next() {
             Line::Some(s) => bytes_to_box_str(s),
             _ => {
                 if SERV_STAYOPEN == 0 {
diff --git a/src/header/regex/mod.rs b/src/header/regex/mod.rs
index eedc462822bb1bba45ff3c0a27792ed0d3edad01..d3eab6c92c3bfc6e6b8930e5a2746175d5dc7b3c 100644
--- a/src/header/regex/mod.rs
+++ b/src/header/regex/mod.rs
@@ -1,7 +1,6 @@
 //! regex.h implementation, following http://pubs.opengroup.org/onlinepubs/7908799/xsh/regex.h.html
 
 use alloc::borrow::Cow;
-use alloc::boxed::Box;
 use alloc::vec::Vec;
 use core::{mem, slice, ptr};
 use header::string::strlen;
@@ -116,7 +115,7 @@ pub extern "C" fn regexec(regex: *const regex_t, input: *const c_char,
 
     // Allow specifying a compiler argument to the executor and vise versa
     // because why not?
-    let mut flags = regex.cflags | eflags;
+    let flags = regex.cflags | eflags;
 
     let input = unsafe { slice::from_raw_parts(input as *const u8, strlen(input)) };
 
diff --git a/src/header/stdio/default.rs b/src/header/stdio/default.rs
index 5d3fe1e0a296319dab0f068767c6970858fe5cec..952ac55622c90e86c4b48c7e0e8c3f252e1e3ae9 100644
--- a/src/header/stdio/default.rs
+++ b/src/header/stdio/default.rs
@@ -1,7 +1,6 @@
-use super::{constants, Buffer, BUFSIZ, FILE, UNGET};
+use super::{constants, Buffer, BUFSIZ, FILE};
 use core::cell::UnsafeCell;
 use core::ptr;
-use core::sync::atomic::AtomicBool;
 
 use fs::File;
 use io::LineWriter;
diff --git a/src/header/stdio/helpers.rs b/src/header/stdio/helpers.rs
index 3fff7993573353808e3fc610dff1558ee5552ff1..126c009a0375237fe55d9ca35057e08a4509c9ac 100644
--- a/src/header/stdio/helpers.rs
+++ b/src/header/stdio/helpers.rs
@@ -1,6 +1,4 @@
 use alloc::boxed::Box;
-use core::sync::atomic::AtomicBool;
-use core::{mem, ptr};
 
 use fs::File;
 use header::errno;
diff --git a/src/header/stdio/mod.rs b/src/header/stdio/mod.rs
index 0653c1d6e9aa07a1338bc95368971190038c7685..e94884a901ee5095cd172d6e30a295d82a62f68c 100644
--- a/src/header/stdio/mod.rs
+++ b/src/header/stdio/mod.rs
@@ -3,10 +3,9 @@
 use alloc::borrow::{Borrow, BorrowMut};
 use alloc::boxed::Box;
 use alloc::vec::Vec;
+use core::fmt;
 use core::fmt::Write as WriteFmt;
-use core::fmt::{self, Error};
 use core::ops::{Deref, DerefMut};
-use core::sync::atomic::{self, AtomicBool, Ordering};
 use core::{ptr, str, slice};
 use va_list::VaList as va_list;
 
@@ -16,7 +15,7 @@ use header::errno::{self, STR_ERROR};
 use header::fcntl;
 use header::stdlib::mkstemp;
 use header::string::strlen;
-use io::{self, BufRead, LineWriter, SeekFrom, Read, Write};
+use io::{self, BufRead, LineWriter, Read, Write};
 use mutex::Mutex;
 use platform::types::*;
 use platform::{Pal, Sys};
@@ -513,7 +512,7 @@ pub extern "C" fn ftell(stream: *mut FILE) -> c_long {
 /// Get the current position of the cursor in the file
 #[no_mangle]
 pub extern "C" fn ftello(stream: *mut FILE) -> off_t {
-    let mut stream = unsafe { &mut *stream }.lock();
+    let stream = unsafe { &mut *stream }.lock();
     let pos = Sys::lseek(*stream.file, 0, SEEK_CUR);
     if pos < 0 {
         return -1;
diff --git a/src/header/stdio/printf.rs b/src/header/stdio/printf.rs
index 00d7153621996a25874760a8fe250c662d24cac8..2664b7f0cfd4592dcd07ea1dfc92455bb36c6080 100644
--- a/src/header/stdio/printf.rs
+++ b/src/header/stdio/printf.rs
@@ -1,14 +1,12 @@
 use alloc::string::String;
 use alloc::string::ToString;
 use alloc::vec::Vec;
-use core::fmt::Write as CoreWrite;
 use core::ops::Range;
-use core::{fmt, ptr, slice, str};
+use core::{fmt, slice};
 
-use c_str::CStr;
 use io::{self, Write};
+use platform;
 use platform::types::*;
-use platform::{self, WriteByte};
 use va_list::{VaList, VaPrimitive};
 
 #[derive(PartialEq, Eq)]
@@ -221,7 +219,7 @@ fn fmt_float_exp<W: Write>(
     }
 
     let string = float_string(float, precision, trim);
-    let mut len = string.len() + 2 + 2.max(exp_len);
+    let len = string.len() + 2 + 2.max(exp_len);
 
     pad(w, !left, b' ', len..pad_space)?;
     let bytes = if string.starts_with('-') {
@@ -261,8 +259,8 @@ fn fmt_float_normal<W: Write>(
 
     Ok(string.len())
 }
-unsafe fn inner_printf<W: Write>(w: W, format: *const c_char, mut ap: VaList) -> io::Result<c_int> {
-    let mut w = &mut platform::CountingWriter::new(w);
+unsafe fn inner_printf<W: Write>(w: W, format: *const c_char, ap: VaList) -> io::Result<c_int> {
+    let w = &mut platform::CountingWriter::new(w);
     let mut ap = BufferedVaList::new(ap);
     let mut format = format as *const u8;
 
diff --git a/src/header/string/mod.rs b/src/header/string/mod.rs
index 879fb89309d7a85b7e504656339d97073ca73207..9f0ce210f2c25f35a35003c057f31e9b7334c22e 100644
--- a/src/header/string/mod.rs
+++ b/src/header/string/mod.rs
@@ -366,7 +366,7 @@ pub unsafe extern "C" fn strspn(s1: *const c_char, s2: *const c_char) -> size_t
     inner_strspn(s1, s2, true)
 }
 
-unsafe fn inner_strstr(mut haystack: *const c_char, mut needle: *const c_char, mask: c_char) -> *mut c_char {
+unsafe fn inner_strstr(mut haystack: *const c_char, needle: *const c_char, mask: c_char) -> *mut c_char {
     while *haystack != 0 {
         let mut i = 0;
         loop {
diff --git a/src/header/strings/mod.rs b/src/header/strings/mod.rs
index 5443ebc738b322b19913916f6c4742d1ce828a22..562f5d805721a427b0c2b43545ffb4583898bb52 100644
--- a/src/header/strings/mod.rs
+++ b/src/header/strings/mod.rs
@@ -1,6 +1,5 @@
 //! strings implementation for Redox, following http://pubs.opengroup.org/onlinepubs/7908799/xsh/strings.h.html
 
-use alloc::vec::Vec;
 use core::ptr;
 
 use platform::types::*;
@@ -66,7 +65,7 @@ pub unsafe extern "C" fn rindex(mut s: *const c_char, c: c_int) -> *mut c_char {
 }
 
 #[no_mangle]
-pub unsafe extern "C" fn strcasecmp(mut first: *const c_char, mut second: *const c_char) -> c_int {
+pub unsafe extern "C" fn strcasecmp(first: *const c_char, second: *const c_char) -> c_int {
     strncasecmp(first, second, size_t::max_value())
 }
 
diff --git a/src/header/sys_ioctl/mod.rs b/src/header/sys_ioctl/mod.rs
index fe72041e0e688cdd6feba352a432787811b89270..bf3b8d69a7ef85943000f27e2004b885afe411ca 100644
--- a/src/header/sys_ioctl/mod.rs
+++ b/src/header/sys_ioctl/mod.rs
@@ -24,7 +24,7 @@ pub struct winsize {
 #[cfg(target_os = "linux")]
 pub mod inner {
     use platform::types::*;
-    use platform::{Pal, Sys};
+    use platform::Sys;
 
     #[no_mangle]
     pub extern "C" fn ioctl(fd: c_int, request: c_ulong, out: *mut c_void) -> c_int {
diff --git a/src/header/sys_stat/mod.rs b/src/header/sys_stat/mod.rs
index 2c3208e83b00cb6bd4cfa73d09d81e058ede557f..fe0ea6954dbe643f9480c018147491a5e1f20361 100644
--- a/src/header/sys_stat/mod.rs
+++ b/src/header/sys_stat/mod.rs
@@ -3,7 +3,6 @@
 use c_str::CStr;
 use header::fcntl::{O_NOFOLLOW, O_PATH};
 use header::time::timespec;
-use platform;
 use platform::types::*;
 use platform::{Pal, Sys};
 
diff --git a/src/header/sys_utsname/mod.rs b/src/header/sys_utsname/mod.rs
index 3a6b766d4a0c36e0d8c37c8af64ee6466a69fc14..9e74d6f181fb56d229773d67a1f2e661687a9f36 100644
--- a/src/header/sys_utsname/mod.rs
+++ b/src/header/sys_utsname/mod.rs
@@ -17,7 +17,7 @@ pub struct utsname {
 #[cfg(target_os = "linux")]
 mod inner {
     use super::*;
-    use platform::{Pal, Sys};
+    use platform::Sys;
 
     #[no_mangle]
     pub unsafe extern "C" fn uname(uts: *mut utsname) -> c_int {
diff --git a/src/header/unistd/getopt.rs b/src/header/unistd/getopt.rs
index b58186ea2a03eda9714f51f051d68f618c8db439..d19ba5b410bcaf69dcd49f62d7b997d4ac527bfc 100644
--- a/src/header/unistd/getopt.rs
+++ b/src/header/unistd/getopt.rs
@@ -2,7 +2,7 @@
 
 use core::ptr;
 
-use header::{getopt, stdio, string};
+use header::getopt;
 use platform::types::*;
 
 #[allow(non_upper_case_globals)]
diff --git a/src/header/unistd/mod.rs b/src/header/unistd/mod.rs
index 80a6385544f4526ef95d3f35a8ec1c1ec52c7030..ab0373722ee333b7eadcae7efde13524ab600644 100644
--- a/src/header/unistd/mod.rs
+++ b/src/header/unistd/mod.rs
@@ -3,7 +3,7 @@
 use core::{ptr, slice};
 
 use c_str::CStr;
-use header::{limits, sys_time};
+use header::limits;
 use header::time::timespec;
 use platform;
 use platform::types::*;
diff --git a/src/lib.rs b/src/lib.rs
index 189cca34fd6f8400909bb1fddb47e823efed63f9..a9f19ab240204e725fe5731dc4ffa682c697c791 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -7,7 +7,6 @@
 #![feature(const_fn)]
 #![feature(const_vec_new)]
 #![feature(core_intrinsics)]
-#![feature(extern_prelude)]
 #![feature(global_asm)]
 #![feature(lang_items)]
 #![feature(linkage)]
diff --git a/src/platform/linux/mod.rs b/src/platform/linux/mod.rs
index a2df0e66d9775b501bd6efc2f49830ef4a3e1a3d..ba223144d5eb85fef1f9e18c1082a56ea72021a8 100644
--- a/src/platform/linux/mod.rs
+++ b/src/platform/linux/mod.rs
@@ -1,14 +1,12 @@
-use alloc::vec::Vec;
-use core::fmt::Write as _WriteFmt;
 use core::{mem, ptr};
 use core_io::Write;
 
 use super::types::*;
-use super::{errno, FileWriter, Pal};
+use super::{errno, Pal};
 use c_str::CStr;
 use fs::File;
 use header::dirent::dirent;
-use header::errno::{EINVAL, ENOSYS};
+use header::errno::EINVAL;
 use header::fcntl;
 use header::signal::SIGCHLD;
 use header::sys_ioctl::{winsize, TCGETS, TCSETS, TIOCGWINSZ};
diff --git a/src/platform/pal/mod.rs b/src/platform/pal/mod.rs
index caea5473e8ca99187f3bb864ade7325e06d7436b..f2df15baf443b7703d68c39df70bc3874301f86b 100644
--- a/src/platform/pal/mod.rs
+++ b/src/platform/pal/mod.rs
@@ -1,12 +1,9 @@
 use super::types::*;
 use c_str::CStr;
 use header::dirent::dirent;
-//use header::sys_resource::rusage;
 use header::sys_select::fd_set;
 use header::sys_stat::stat;
-use header::sys_time::{itimerval, timeval, timezone};
-//use header::sys_times::tms;
-use header::sys_utsname::utsname;
+use header::sys_time::{timeval, timezone};
 use header::termios::termios;
 use header::time::timespec;
 
diff --git a/src/platform/pal/signal.rs b/src/platform/pal/signal.rs
index b6ffa526dafe1fbd72a9b186027319fa9d752855..644012e8bec74472a8af2377538611a790571e23 100644
--- a/src/platform/pal/signal.rs
+++ b/src/platform/pal/signal.rs
@@ -1,6 +1,6 @@
 use super::super::types::*;
 use super::super::Pal;
-use header::signal::{sigaction, sigset_t};
+use header::signal::sigaction;
 
 pub trait PalSignal: Pal {
     fn kill(pid: pid_t, sig: c_int) -> c_int;
diff --git a/src/start.rs b/src/start.rs
index 0d7d832e0de86e47f6e560f623e8ac119601f33c..7de69a57efaf00ad642127ee7a84bb1ac01e5a37 100644
--- a/src/start.rs
+++ b/src/start.rs
@@ -4,7 +4,6 @@ use core::ptr;
 use header::{stdio, stdlib};
 use platform;
 use platform::types::*;
-use platform::{Pal, Sys};
 
 #[repr(C)]
 pub struct Stack {