diff --git a/src/unix/bsd/netbsdlike/netbsd/mod.rs b/src/unix/bsd/netbsdlike/netbsd/mod.rs
index 47f17eba..47e077eb 100644
--- a/src/unix/bsd/netbsdlike/netbsd/mod.rs
+++ b/src/unix/bsd/netbsdlike/netbsd/mod.rs
@@ -272,6 +272,7 @@ pub const O_NOSIGPIPE: ::c_int = 0x1000000;
 pub const O_SEARCH: ::c_int = 0x800000;
 pub const O_DIRECTORY: ::c_int = 0x200000;
 pub const O_DIRECT : ::c_int = 0x00080000;
+pub const O_RSYNC : ::c_int = 0x00020000;
 
 pub const MS_SYNC : ::c_int = 0x4;
 pub const MS_INVALIDATE : ::c_int = 0x2;
diff --git a/src/unix/bsd/netbsdlike/openbsdlike/mod.rs b/src/unix/bsd/netbsdlike/openbsdlike/mod.rs
index 68db12b3..d7fe04e7 100644
--- a/src/unix/bsd/netbsdlike/openbsdlike/mod.rs
+++ b/src/unix/bsd/netbsdlike/openbsdlike/mod.rs
@@ -141,6 +141,7 @@ pub const UT_HOSTSIZE: usize = 256;
 
 pub const O_CLOEXEC: ::c_int = 0x10000;
 pub const O_DIRECTORY: ::c_int = 0x20000;
+pub const O_RSYNC: ::c_int = O_SYNC;
 
 pub const MS_SYNC : ::c_int = 0x0002;
 pub const MS_INVALIDATE : ::c_int = 0x0004;