diff --git a/src/unix/notbsd/linux/other/b64/x86_64.rs b/src/unix/notbsd/linux/other/b64/x86_64.rs
index 5689aaa2..7596eba4 100644
--- a/src/unix/notbsd/linux/other/b64/x86_64.rs
+++ b/src/unix/notbsd/linux/other/b64/x86_64.rs
@@ -427,6 +427,10 @@ pub const F_SETOWN: ::c_int = 8;
 pub const F_SETLK: ::c_int = 6;
 pub const F_SETLKW: ::c_int = 7;
 
+pub const F_RDLCK: ::c_int = 0;
+pub const F_WRLCK: ::c_int = 1;
+pub const F_UNLCK: ::c_int = 2;
+
 pub const SFD_NONBLOCK: ::c_int = 0x0800;
 
 pub const TIOCEXCL: ::c_ulong = 0x540C;