diff --git a/src/unix/redox/mod.rs b/src/unix/redox/mod.rs
index 61c4debb775e3..0e0746e138678 100644
--- a/src/unix/redox/mod.rs
+++ b/src/unix/redox/mod.rs
@@ -48,6 +48,9 @@ pub type suseconds_t = ::c_int;
 pub type tcflag_t = u32;
 pub type time_t = ::c_longlong;
 pub type id_t = ::c_uint;
+pub type pid_t = usize;
+pub type uid_t = u32;
+pub type gid_t = u32;
 
 #[cfg_attr(feature = "extra_traits", derive(Debug))]
 pub enum timezone {}
@@ -256,6 +259,12 @@ s! {
         pub tm_gmtoff: ::c_long,
         pub tm_zone: *const ::c_char,
     }
+
+    pub struct ucred {
+        pub pid: pid_t,
+        pub uid: uid_t,
+        pub gid: gid_t,
+    }
 }
 
 pub const UTSLENGTH: usize = 65;