diff --git a/src/libpanic_unwind/gcc.rs b/src/libpanic_unwind/gcc.rs
index 8df68da3786..3c46072e17e 100644
--- a/src/libpanic_unwind/gcc.rs
+++ b/src/libpanic_unwind/gcc.rs
@@ -57,6 +57,7 @@
 #![allow(private_no_mangle_fns)]
 
 use core::any::Any;
+use core::ptr;
 use alloc::boxed::Box;
 
 use unwind as uw;
@@ -88,7 +89,7 @@ pub unsafe fn panic(data: Box<Any + Send>) -> u32 {
 }
 
 pub fn payload() -> *mut u8 {
-    0 as *mut u8
+    ptr::null_mut()
 }
 
 pub unsafe fn cleanup(ptr: *mut u8) -> Box<Any + Send> {
diff --git a/src/libpanic_unwind/seh64_gnu.rs b/src/libpanic_unwind/seh64_gnu.rs
index 12e1a764c5f..56801e8cb6b 100644
--- a/src/libpanic_unwind/seh64_gnu.rs
+++ b/src/libpanic_unwind/seh64_gnu.rs
@@ -18,6 +18,7 @@ use alloc::boxed::Box;
 
 use core::any::Any;
 use core::intrinsics;
+use core::ptr;
 use dwarf::eh;
 use windows as c;
 
@@ -50,7 +51,7 @@ pub unsafe fn panic(data: Box<Any + Send>) -> u32 {
 }
 
 pub fn payload() -> *mut u8 {
-    0 as *mut u8
+    ptr::null_mut()
 }
 
 pub unsafe fn cleanup(ptr: *mut u8) -> Box<Any + Send> {
diff --git a/src/librustc_trans/base.rs b/src/librustc_trans/base.rs
index c080d1f06d0..8fadb191e25 100644
--- a/src/librustc_trans/base.rs
+++ b/src/librustc_trans/base.rs
@@ -98,6 +98,7 @@ use libc::c_uint;
 use std::ffi::{CStr, CString};
 use std::cell::{Cell, RefCell};
 use std::collections::{HashMap, HashSet};
+use std::ptr;
 use std::rc::Rc;
 use std::str;
 use std::{i8, i16, i32, i64};
@@ -2304,7 +2305,7 @@ pub fn maybe_create_entry_wrapper(ccx: &CrateContext) {
                                                  start_fn,
                                                  args.as_ptr(),
                                                  args.len() as c_uint,
-                                                 0 as *mut _,
+                                                 ptr::null_mut(),
                                                  noname());
 
             llvm::LLVMBuildRet(bld, result);
diff --git a/src/librustc_trans/builder.rs b/src/librustc_trans/builder.rs
index d4156986600..e88257dcd4c 100644
--- a/src/librustc_trans/builder.rs
+++ b/src/librustc_trans/builder.rs
@@ -177,7 +177,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
 
         check_call("invoke", llfn, args);
 
-        let bundle = bundle.as_ref().map(|b| b.raw()).unwrap_or(0 as *mut _);
+        let bundle = bundle.as_ref().map(|b| b.raw()).unwrap_or(ptr::null_mut());
 
         unsafe {
             llvm::LLVMRustBuildInvoke(self.llbuilder,
@@ -859,7 +859,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
 
         check_call("call", llfn, args);
 
-        let bundle = bundle.as_ref().map(|b| b.raw()).unwrap_or(0 as *mut _);
+        let bundle = bundle.as_ref().map(|b| b.raw()).unwrap_or(ptr::null_mut());
 
         unsafe {
             llvm::LLVMRustBuildCall(self.llbuilder, llfn, args.as_ptr(),
@@ -961,7 +961,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
             self.count_insn("trap");
             llvm::LLVMRustBuildCall(self.llbuilder, t,
                                     args.as_ptr(), args.len() as c_uint,
-                                    0 as *mut _,
+                                    ptr::null_mut(),
                                     noname());
         }
     }
@@ -1000,7 +1000,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                        parent: Option<ValueRef>,
                        args: &[ValueRef]) -> ValueRef {
         self.count_insn("cleanuppad");
-        let parent = parent.unwrap_or(0 as *mut _);
+        let parent = parent.unwrap_or(ptr::null_mut());
         let name = CString::new("cleanuppad").unwrap();
         let ret = unsafe {
             llvm::LLVMRustBuildCleanupPad(self.llbuilder,
@@ -1016,7 +1016,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
     pub fn cleanup_ret(&self, cleanup: ValueRef,
                        unwind: Option<BasicBlockRef>) -> ValueRef {
         self.count_insn("cleanupret");
-        let unwind = unwind.unwrap_or(0 as *mut _);
+        let unwind = unwind.unwrap_or(ptr::null_mut());
         let ret = unsafe {
             llvm::LLVMRustBuildCleanupRet(self.llbuilder, cleanup, unwind)
         };
@@ -1052,8 +1052,8 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                         unwind: Option<BasicBlockRef>,
                         num_handlers: usize) -> ValueRef {
         self.count_insn("catchswitch");
-        let parent = parent.unwrap_or(0 as *mut _);
-        let unwind = unwind.unwrap_or(0 as *mut _);
+        let parent = parent.unwrap_or(ptr::null_mut());
+        let unwind = unwind.unwrap_or(ptr::null_mut());
         let name = CString::new("catchswitch").unwrap();
         let ret = unsafe {
             llvm::LLVMRustBuildCatchSwitch(self.llbuilder, parent, unwind,
diff --git a/src/libstd/sync/once.rs b/src/libstd/sync/once.rs
index e9ea465cc99..54c1fe6c564 100644
--- a/src/libstd/sync/once.rs
+++ b/src/libstd/sync/once.rs
@@ -65,6 +65,7 @@
 // it!
 
 use marker;
+use ptr;
 use sync::atomic::{AtomicUsize, AtomicBool, Ordering};
 use thread::{self, Thread};
 
@@ -297,7 +298,7 @@ impl Once {
                     let mut node = Waiter {
                         thread: Some(thread::current()),
                         signaled: AtomicBool::new(false),
-                        next: 0 as *mut Waiter,
+                        next: ptr::null_mut(),
                     };
                     let me = &mut node as *mut Waiter as usize;
                     assert!(me & STATE_MASK == 0);
diff --git a/src/libstd/sys/unix/os.rs b/src/libstd/sys/unix/os.rs
index 21ce6b19ceb..5f7588de776 100644
--- a/src/libstd/sys/unix/os.rs
+++ b/src/libstd/sys/unix/os.rs
@@ -227,11 +227,11 @@ pub fn current_exe() -> io::Result<PathBuf> {
                        libc::KERN_PROC_ARGV];
         let mib = mib.as_mut_ptr();
         let mut argv_len = 0;
-        cvt(libc::sysctl(mib, 4, 0 as *mut _, &mut argv_len,
-                         0 as *mut _, 0))?;
+        cvt(libc::sysctl(mib, 4, ptr::null_mut(), &mut argv_len,
+                         ptr::null_mut(), 0))?;
         let mut argv = Vec::<*const libc::c_char>::with_capacity(argv_len as usize);
         cvt(libc::sysctl(mib, 4, argv.as_mut_ptr() as *mut _,
-                         &mut argv_len, 0 as *mut _, 0))?;
+                         &mut argv_len, ptr::null_mut(), 0))?;
         argv.set_len(argv_len as usize);
         if argv[0].is_null() {
             return Err(io::Error::new(io::ErrorKind::Other,
diff --git a/src/libstd/sys/unix/pipe.rs b/src/libstd/sys/unix/pipe.rs
index 2dde9c0e615..01059413338 100644
--- a/src/libstd/sys/unix/pipe.rs
+++ b/src/libstd/sys/unix/pipe.rs
@@ -14,6 +14,7 @@ use cmp;
 use io;
 use libc::{self, c_int};
 use mem;
+use ptr;
 use sys::cvt_r;
 use sys::fd::FileDesc;
 
@@ -92,8 +93,8 @@ pub fn read2(p1: AnonPipe,
             let mut read: libc::fd_set = mem::zeroed();
             libc::FD_SET(p1.raw(), &mut read);
             libc::FD_SET(p2.raw(), &mut read);
-            libc::select(max + 1, &mut read, 0 as *mut _, 0 as *mut _,
-                         0 as *mut _)
+            libc::select(max + 1, &mut read, ptr::null_mut(), ptr::null_mut(),
+                         ptr::null_mut())
         })?;
 
         // Read as much as we can from each pipe, ignoring EWOULDBLOCK or
diff --git a/src/libstd/sys/unix/process.rs b/src/libstd/sys/unix/process.rs
index 98cfdcdf110..d68867fb3d2 100644
--- a/src/libstd/sys/unix/process.rs
+++ b/src/libstd/sys/unix/process.rs
@@ -96,7 +96,7 @@ impl Command {
         let mut saw_nul = false;
         let program = os2c(program, &mut saw_nul);
         Command {
-            argv: vec![program.as_ptr(), 0 as *const _],
+            argv: vec![program.as_ptr(), ptr::null()],
             program: program,
             args: Vec::new(),
             env: None,
@@ -117,7 +117,7 @@ impl Command {
         // pointer.
         let arg = os2c(arg, &mut self.saw_nul);
         self.argv[self.args.len() + 1] = arg.as_ptr();
-        self.argv.push(0 as *const _);
+        self.argv.push(ptr::null());
 
         // Also make sure we keep track of the owned value to schedule a
         // destructor for this memory.
@@ -134,7 +134,7 @@ impl Command {
                 envp.push(s.as_ptr());
                 map.insert(k, (envp.len() - 1, s));
             }
-            envp.push(0 as *const _);
+            envp.push(ptr::null());
             self.env = Some(map);
             self.envp = Some(envp);
         }
@@ -158,7 +158,7 @@ impl Command {
             Entry::Vacant(e) => {
                 let len = envp.len();
                 envp[len - 1] = new_key.as_ptr();
-                envp.push(0 as *const _);
+                envp.push(ptr::null());
                 e.insert((len - 1, new_key));
             }
         }
@@ -183,7 +183,7 @@ impl Command {
 
     pub fn env_clear(&mut self) {
         self.env = Some(HashMap::new());
-        self.envp = Some(vec![0 as *const _]);
+        self.envp = Some(vec![ptr::null()]);
     }
 
     pub fn cwd(&mut self, dir: &OsStr) {
diff --git a/src/libstd/sys/unix/time.rs b/src/libstd/sys/unix/time.rs
index 68eebba9e7b..a08cec38f73 100644
--- a/src/libstd/sys/unix/time.rs
+++ b/src/libstd/sys/unix/time.rs
@@ -9,8 +9,8 @@
 // except according to those terms.
 
 use cmp::Ordering;
-use time::Duration;
 use libc;
+use time::Duration;
 
 pub use self::inner::{Instant, SystemTime, UNIX_EPOCH};
 
@@ -164,12 +164,14 @@ mod inner {
 
     impl SystemTime {
         pub fn now() -> SystemTime {
+            use ptr;
+
             let mut s = libc::timeval {
                 tv_sec: 0,
                 tv_usec: 0,
             };
             cvt(unsafe {
-                libc::gettimeofday(&mut s, 0 as *mut _)
+                libc::gettimeofday(&mut s, ptr::null_mut())
             }).unwrap();
             return SystemTime::from(s)
         }
diff --git a/src/libstd/sys/windows/handle.rs b/src/libstd/sys/windows/handle.rs
index 74546bb893b..d10abae2865 100644
--- a/src/libstd/sys/windows/handle.rs
+++ b/src/libstd/sys/windows/handle.rs
@@ -46,10 +46,10 @@ impl Handle {
 
     pub fn new_event(manual: bool, init: bool) -> io::Result<Handle> {
         unsafe {
-            let event = c::CreateEventW(0 as *mut _,
+            let event = c::CreateEventW(ptr::null_mut(),
                                         manual as c::BOOL,
                                         init as c::BOOL,
-                                        0 as *const _);
+                                        ptr::null());
             if event.is_null() {
                 Err(io::Error::last_os_error())
             } else {
diff --git a/src/libstd/sys/windows/pipe.rs b/src/libstd/sys/windows/pipe.rs
index 8631a63d653..6e9c67051a6 100644
--- a/src/libstd/sys/windows/pipe.rs
+++ b/src/libstd/sys/windows/pipe.rs
@@ -12,9 +12,10 @@ use prelude::v1::*;
 use os::windows::prelude::*;
 
 use ffi::OsStr;
-use path::Path;
 use io;
 use mem;
+use path::Path;
+use ptr;
 use rand::{self, Rng};
 use slice;
 use sys::c;
@@ -66,7 +67,7 @@ pub fn anon_pipe() -> io::Result<(AnonPipe, AnonPipe)> {
                                              4096,
                                              4096,
                                              0,
-                                             0 as *mut _);
+                                             ptr::null_mut());
 
             // We pass the FILE_FLAG_FIRST_PIPE_INSTANCE flag above, and we're
             // also just doing a best effort at selecting a unique name. If
diff --git a/src/libtest/lib.rs b/src/libtest/lib.rs
index c90c93e75ac..248f6f98650 100644
--- a/src/libtest/lib.rs
+++ b/src/libtest/lib.rs
@@ -959,6 +959,8 @@ fn get_concurrency() -> usize {
               target_os = "bitrig",
               target_os = "netbsd"))]
     fn num_cpus() -> usize {
+        use std::ptr;
+
         let mut cpus: libc::c_uint = 0;
         let mut cpus_size = std::mem::size_of_val(&cpus);
 
@@ -972,7 +974,7 @@ fn get_concurrency() -> usize {
                              2,
                              &mut cpus as *mut _ as *mut _,
                              &mut cpus_size as *mut _ as *mut _,
-                             0 as *mut _,
+                             ptr::null_mut(),
                              0);
             }
             if cpus < 1 {
@@ -984,6 +986,8 @@ fn get_concurrency() -> usize {
 
     #[cfg(target_os = "openbsd")]
     fn num_cpus() -> usize {
+        use std::ptr;
+
         let mut cpus: libc::c_uint = 0;
         let mut cpus_size = std::mem::size_of_val(&cpus);
         let mut mib = [libc::CTL_HW, libc::HW_NCPU, 0, 0];
@@ -993,7 +997,7 @@ fn get_concurrency() -> usize {
                          2,
                          &mut cpus as *mut _ as *mut _,
                          &mut cpus_size as *mut _ as *mut _,
-                         0 as *mut _,
+                         ptr::null_mut(),
                          0);
         }
         if cpus < 1 {