diff --git a/src/libstd/sys/unix/process/magenta.rs b/src/libstd/sys/unix/process/magenta.rs
index 319fbce35cd7b..2bb005be4ec93 100644
--- a/src/libstd/sys/unix/process/magenta.rs
+++ b/src/libstd/sys/unix/process/magenta.rs
@@ -23,7 +23,6 @@ pub type mx_rights_t = u32;
 pub type mx_status_t = i32;
 
 pub type mx_size_t = usize;
-pub type mx_ssize_t = isize;
 
 pub const MX_HANDLE_INVALID: mx_handle_t = 0;