diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7d59d217bd..3bddf62a0d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -12,6 +12,8 @@ This project adheres to [Semantic Versioning](http://semver.org/).
   ([#551](https://github.com/nix-rust/nix/pull/551))
 - Added `nix::pty::{grantpt, posix_openpt, ptsname/ptsname_r, unlockpt}`
   ([#556](https://github.com/nix-rust/nix/pull/556)
+- Added `nix::sys::user`
+  ([#606](https://github.com/nix-rust/nix/pull/606)
 
 ### Changed
 - Marked `sys::mman::{ mmap, munmap, madvise, munlock, msync }` as unsafe.
diff --git a/src/sys/mod.rs b/src/sys/mod.rs
index 7675f94448..02a8f468f9 100644
--- a/src/sys/mod.rs
+++ b/src/sys/mod.rs
@@ -59,6 +59,11 @@ pub mod time;
           )]
 pub mod ptrace;
 
+#[cfg(any(target_arch = "x86",
+          target_arch = "x86_64")
+          )]
+pub mod user;
+
 pub mod select;
 
 #[cfg(all(target_os = "linux",
diff --git a/src/sys/user.rs b/src/sys/user.rs
new file mode 100644
index 0000000000..046e4c6c1a
--- /dev/null
+++ b/src/sys/user.rs
@@ -0,0 +1,177 @@
+
+
+#[cfg(any(target_arch = "x86_64"))]
+use libc::{c_ushort, c_uint, c_char, c_int, c_longlong, c_ulonglong};
+#[cfg(any(target_arch = "x86"))]
+use libc::{c_ushort, c_char, c_int, c_long, c_ulong};
+
+use libc::size_t;
+
+pub type Eflag = size_t;
+
+const EFLAG_CARRY: Eflag = 0x1;
+const EFLAG_PARITY: Eflag = 0x1 << 2;
+const EFLAG_AUXILIARY_CARRY: Eflag  =  0x1 << 4;
+const EFLAG_ZERO: Eflag  =  0x1 << 6;
+const EFLAG_SIGN: Eflag  =  0x1 << 7;
+const EFLAG_TRAP: Eflag  =  0x1 << 8;
+const EFLAG_INTERRUPT_ENABLE: Eflag  =  0x1 << 9;
+const EFLAG_DIRECTION: Eflag  =  0x1 << 10;
+const EFLAG_OVERFLOW: Eflag  =  0x1 << 11;
+const EFLAG_IOPRIVILEGE_1: Eflag  =  0x1 << 12;
+const EFLAG_IOPRIVILEGE_2: Eflag  =  0x1 << 13;
+const EFLAG_NESTEDTASK: Eflag  =  0x1 << 14;
+const EFLAG_RESUME: Eflag  =  0x1 << 16;
+const EFLAG_VIRTUAL_80086_MODE: Eflag  =  0x1 << 17;
+const EFLAG_ALIGNMENT_CHECK: Eflag  =  0x1 << 18;
+const EFLAG_VIRTUAL_INTERRUPT: Eflag  =  0x1 << 19;
+const EFLAG_VIRTUAL_INTERRUPT_PENDING: Eflag  =  0x1 << 20;
+const EFLAG_CPUID: Eflag  =  0x1 << 21;
+
+
+#[repr(C)]
+#[cfg(any(target_arch = "x86_64"))]
+pub struct FpRegs {
+    pub cwd: c_ushort,
+    pub swd: c_ushort,
+    pub ftw: c_ushort,
+    pub fop: c_ushort,
+    pub rip: c_ulonglong,
+    pub rdp: c_ulonglong,
+    pub mxcsr: c_uint,
+    pub mxcr_mask: c_uint,
+    pub st_space: [c_uint; 32],
+    pub xmm_space: [c_uint; 64],
+    pub padding: [c_uint; 24],
+}
+
+
+#[repr(C)]
+#[cfg(any(target_arch = "x86_64"))]
+pub struct Regs {
+    pub r15: c_ulonglong,
+    pub r14: c_ulonglong,
+    pub r13: c_ulonglong,
+    pub r12: c_ulonglong,
+    pub rbp: c_ulonglong,
+    pub rbx: c_ulonglong,
+    pub r11: c_ulonglong,
+    pub r10: c_ulonglong,
+    pub r9: c_ulonglong,
+    pub r8: c_ulonglong,
+    pub rax: c_ulonglong,
+    pub rcx: c_ulonglong,
+    pub rdx: c_ulonglong,
+    pub rsi: c_ulonglong,
+    pub rdi: c_ulonglong,
+    pub orig_rax: c_ulonglong,
+    pub rip: c_ulonglong,
+    pub cs: c_ulonglong,
+    pub eflags: Eflag,
+    pub rsp: c_ulonglong,
+    pub ss: c_ulonglong,
+    pub fs_base: c_ulonglong,
+    pub gs_base: c_ulonglong,
+    pub ds: c_ulonglong,
+    pub es: c_ulonglong,
+    pub fs: c_ulonglong,
+    pub gs: c_ulonglong,
+}
+
+
+#[repr(C)]
+#[cfg(any(target_arch = "x86_64"))]
+pub struct User {
+    regs: Regs,
+    u_fpvalid: c_int,
+    i387: FpRegs,
+    u_tsize: c_ulonglong,
+    u_dsize: c_ulonglong,
+    u_ssize: c_ulonglong,
+    start_code: c_ulonglong,
+    start_stack: c_ulonglong,
+    signal: c_longlong,
+    reserved: c_int,
+    u_ar0: *mut Regs,
+    u_fpstate: *mut FpRegs,
+    magic: c_ulonglong,
+    u_comm: [c_char; 32],
+    u_debugreg: [c_ulonglong; 8]
+}
+
+
+
+#[repr(C)]
+#[cfg(not(any(target_arch = "x86_64")))]
+pub struct FpRegs {
+    pub cwd: c_long,
+    pub swd: c_long,
+    pub ftw: c_long,
+    pub fip: c_long,
+    pub fcs: c_long,
+    pub foo: c_long,
+    pub fos: c_long,
+    pub st_space: [c_long; 20],
+}
+
+
+#[repr(C)]
+#[cfg(not(any(target_arch = "x86_64")))]
+pub struct FpxRegs {
+    pub cwd: c_ushort,
+    pub swd: c_ushort,
+    pub twd: c_ushort,
+    pub fop: c_ushort,
+    pub fip: c_long,
+    pub fcs: c_long,
+    pub foo: c_long,
+    pub fos: c_long,
+    pub mxcsr: c_long,
+    pub reserved: c_long,
+    pub st_space: [c_long; 32],
+    pub xmm_space: [c_long; 32],
+    pub padding: [c_long; 56],
+}
+
+#[repr(C)]
+#[cfg(not(any(target_arch = "x86_64")))]
+pub struct Regs {
+    pub ebx: c_long,
+    pub ecx: c_long,
+    pub edx: c_long,
+    pub esi: c_long,
+    pub edi: c_long,
+    pub ebp: c_long,
+    pub eax: c_long,
+    pub xds: c_long,
+    pub xes: c_long,
+    pub xfs: c_long,
+    pub xgs: c_long,
+    pub orig_eax: c_long,
+    pub eip: c_long,
+    pub xcs: c_long,
+    pub eflags: Eflag,
+    pub esp: c_long,
+    pub xss: c_long,
+}
+
+
+#[repr(C)]
+#[cfg(not(any(target_arch = "x86_64")))]
+pub struct User {
+    regs: Regs,
+    u_fpvalid: c_int,
+    i387: FpRegs,
+    u_tsize: c_ulong,
+    u_dsize: c_ulong,
+    u_ssize: c_ulong,
+    start_code: c_ulong,
+    start_stack: c_ulong,
+    signal: c_long,
+    reserved: c_int,
+    u_ar0: *mut Regs,
+    u_fpstate: *mut FpRegs,
+    magic: c_ulong,
+    u_comm: [c_char; 32],
+    u_debugreg: [c_int; 8],
+}