diff --git a/src/libos/src/fs/mod.rs b/src/libos/src/fs/mod.rs
index cdaff66d..384a5f1a 100644
--- a/src/libos/src/fs/mod.rs
+++ b/src/libos/src/fs/mod.rs
@@ -20,12 +20,6 @@ mod socket_file;
 mod pipe;
 mod sgx_impl;
 
-// TODO: use the type defined in Rust libc.
-//
-// However, off_t is defined as u64 in the current Rust SGX SDK, which is
-// wrong (see issue https://github.com/baidu/rust-sgx-sdk/issues/46)
-#[allow(non_camel_case_types)]
-pub type off_t = i64;
 
 pub fn do_open(path: &str, flags: u32, mode: u32) -> Result<FileDesc, Error> {
     let flags = OpenFlags::from_bits_truncate(flags);
diff --git a/src/libos/src/prelude.rs b/src/libos/src/prelude.rs
index 2c9708b3..2a1d1ccc 100644
--- a/src/libos/src/prelude.rs
+++ b/src/libos/src/prelude.rs
@@ -1,4 +1,5 @@
 pub use sgx_trts::libc;
+pub use sgx_trts::libc::off_t;
 pub use sgx_types::*;
 use std;
 
@@ -26,8 +27,6 @@ pub use errno::Errno;
 pub use errno::Errno::*;
 pub use errno::Error;
 
-pub use fs::off_t;
-
 macro_rules! debug_trace {
     () => {
         println!("> Line = {}, File = {}", line!(), file!())
diff --git a/src/libos/src/syscall/mod.rs b/src/libos/src/syscall/mod.rs
index 1293aba5..eb0fe921 100644
--- a/src/libos/src/syscall/mod.rs
+++ b/src/libos/src/syscall/mod.rs
@@ -7,7 +7,7 @@
 //! 3. Dispatch the syscall to `do_*` (at this file)
 //! 4. Do some memory checks then call `mod::do_*` (at each module)
 
-use fs::{File, SocketFile, off_t, FileDesc, FileRef};
+use fs::{File, SocketFile, FileDesc, FileRef};
 use prelude::*;
 use process::{ChildProcessFilter, FileAction, pid_t, CloneFlags, FutexFlags, FutexOp};
 use std::ffi::{CStr, CString};
diff --git a/src/libos/src/vm/mod.rs b/src/libos/src/vm/mod.rs
index db1500ab..33585928 100644
--- a/src/libos/src/vm/mod.rs
+++ b/src/libos/src/vm/mod.rs
@@ -1,4 +1,4 @@
-use fs::{off_t, FileDesc};
+use fs::FileDesc;
 use prelude::*;
 use process::{get_current, Process, ProcessRef};
 use std::fmt;