diff --git a/src/header/fcntl/redox.rs b/src/header/fcntl/redox.rs
index c635e9916aeed293bff3387c79ef0821671e5126..ddc189baa8e127498767315e5e7a06ead96ae15e 100644
--- a/src/header/fcntl/redox.rs
+++ b/src/header/fcntl/redox.rs
@@ -1,20 +1,20 @@
 use platform::types::*;
 
-pub const O_RDONLY: c_int = 0x0001;
-pub const O_WRONLY: c_int = 0x0002;
-pub const O_RDWR: c_int = 0x0003;
-pub const O_ACCMODE: c_int = 0x0003;
-pub const O_NONBLOCK: c_int = 0x0004;
-pub const O_APPEND: c_int = 0x0008;
-pub const O_SHLOCK: c_int = 0x0010;
-pub const O_EXLOCK: c_int = 0x0020;
-pub const O_ASYNC: c_int = 0x0040;
-pub const O_FSYNC: c_int = 0x0080;
-pub const O_CLOEXEC: c_int = 0x0100;
-pub const O_CREAT: c_int = 0x0200;
-pub const O_TRUNC: c_int = 0x0400;
-pub const O_EXCL: c_int = 0x0800;
-pub const O_DIRECTORY: c_int = 0x1000;
-pub const O_PATH: c_int = 0x2000;
-pub const O_SYMLINK: c_int = 0x4000;
-pub const O_NOFOLLOW: c_int = 0x8000;
+pub const O_RDONLY: c_int = 0x0001_0000;
+pub const O_WRONLY: c_int = 0x0002_0000;
+pub const O_RDWR: c_int = 0x0003_0000;
+pub const O_ACCMODE: c_int = 0x0003_0000;
+pub const O_NONBLOCK: c_int = 0x0004_0000;
+pub const O_APPEND: c_int = 0x0008_0000;
+pub const O_SHLOCK: c_int = 0x0010_0000;
+pub const O_EXLOCK: c_int = 0x0020_0000;
+pub const O_ASYNC: c_int = 0x0040_0000;
+pub const O_FSYNC: c_int = 0x0080_0000;
+pub const O_CLOEXEC: c_int = 0x0100_0000;
+pub const O_CREAT: c_int = 0x0200_0000;
+pub const O_TRUNC: c_int = 0x0400_0000;
+pub const O_EXCL: c_int = 0x0800_0000;
+pub const O_DIRECTORY: c_int = 0x1000_0000;
+pub const O_PATH: c_int = 0x2000_0000;
+pub const O_SYMLINK: c_int = 0x4000_0000;
+pub const O_NOFOLLOW: c_int = 0x8000_0000;
diff --git a/src/platform/redox/mod.rs b/src/platform/redox/mod.rs
index 1e568bb0ed5897dcedfdf00a11a17cfc534f3e2a..a1b801a3a2211868d4bdad0d0cf6c03bcd69a781 100644
--- a/src/platform/redox/mod.rs
+++ b/src/platform/redox/mod.rs
@@ -679,7 +679,7 @@ impl Pal for Sys {
     fn open(path: &CStr, oflag: c_int, mode: mode_t) -> c_int {
         e(syscall::open(
             path.to_bytes(),
-            ((oflag as usize) << 16) | ((mode as usize) & 0xFFFF),
+            ((oflag as usize) & 0xFFFF_0000) | ((mode as usize) & 0xFFFF),
         )) as c_int
     }